Questions on: Misc. Houseplants
Ron Smith, Horticulturist, NDSU Extension Service
Q: I typically start my own bedding plants each spring using a small greenhouse that I purchased. The problem is that my seedlings develop a very poor stem and root system and become leggy before they fill out. What am I doing wrong? (Jamestown, N.D.)
A: Spindly, weak growth is the result of keeping the air temperature too high and not having enough light. Supplemental lighting is needed to start most seedlings, even in greenhouses.
Q: I've had a corn plant for about two weeks. I've noticed that the leaves are getting brown spots and the tips of some of the leaves also are a bit brown. There's some yellowing of the leaves as well. I have a north-facing window that receives low light. The plant is in a 10-inch diameter pot. I know these plants can be overwatered easily. When I repotted, I noticed the soil was almost muddy around the roots. I removed some of it and added fresh, dry soil to the new pot and gave it a mild watering. What can I do so my corn plant doesn't die? Any suggestions or advice would be greatly appreciated. Thanks! (e-mail reference)
A: All I can do is give you some guidelines to what you might be doing wrong. If you correct them, perhaps the plant will recover. The container should be free-draining, not sealed on the bottom. The water should be room temperature before giving it to the plant. The soil should be allowed to dry down somewhat before being watered again. Usually, these are tough plants. We've had one in our house for more than 10 years. It is potbound, attacked occasionally by our cats and watered or fertilized when the spirit hits us. We also summer the plant outdoors where it is subject to the elements, such as wind, rain and fluctuating temperatures. It sounds like the pot size is about right for the plant's size, so all I can guess is that it has been overwatered.
Q: I repotted a medium-sized aloe vera plant. A couple of its leaves are turning yellow and curling at the tips. I water it once a week. Any advice would be greatly appreciated. (e-mail reference)
A: You probably are overwatering. Allow the soil to dry before watering.
Q: I'm 15 and recently became interested in keeping houseplants. My mother gave me a group of four plants in a small pot. They seemed to be outgrowing the pot, so I decided to repot. It's been about five days and the plants seem to be doing well, except for one. I'm not sure what kind of plant it is (I would be grateful if you could identify it from the pictures), but shortly after repotting, all of the leaves and stems went limp and the plant seems weak. Some of the other plants are slightly limp as well, but nowhere near as much as this one. I watered it slightly after repotting and have kept the soil slightly moist. I used a basic potting mix with slow-release fertilizer. I also should mention that many of the leaves were bent toward the light (it's a climber and was resting on my dresser, so the stalks bent toward the window), but when I repotted, I turned them so they were facing down. My thought was that the leaves would move to face the light again. Could this hurt the plant? Is this a normal reaction to repotting or is there something else wrong? (e-mail reference)
A: Some shock is normal when moving plants from a very crowded potting situation, but a plant going totally limp is not normal and is beyond any hope of recovery. My best guess from the photos is that the plant is some sort of Swedish ivy, but I wouldn't bet the farm on it. You might try cutting off the limp leaves and then keep the root system and crown hydrated to see if some new growth will emerge in the next few weeks. I doubt it will, but you never know unless you try.
Q: My beautiful Norfolk pine is approximately 10 years old. The tree is starting to lose its lower branches. I would like to transplant it outside. The tree would get southwestern exposure for seven months of the year. Where I would like to plant the tree has two walls to protect the tree. What temperatures are bad for Norfolk pine? Is there a possibility of it growing and flourishing outside? I live in Ohio. (e-mail reference)
A: Norfolk Island pine is a tropical plant. Any temperatures approaching the freezing point would kill it. There is no chance it would thrive in any outdoor Ohio environment. This plant is easily air-layered, so you may want to start over to raise a more compact and bushy plant. Go to my Web site at http://www.ag.ndsu.edu/pubs/plantsci/landscap/h1257w.htm for more information.
Q: I received a tree last fall from some people who didn't have room for it anymore. They had it outside all summer. I think it got too cold before I got there to get it. It has lost a lot of branches and needles. A lot of the remaining needles are brown. I've been misting it every day and turning on a humidifier for a while. The humidity in my house has been around 70 percent all winter. Is that high enough? Can you tell me what to do to help the tree? My husband wants to know if it will grow if we cut the top off and plant it. (e-mail reference)
A: There is not much more you can do. If the tree is going to recover, it will with the care you are giving it. Cutting off the top and planting it will not work because it will not root.
Q: I have had a China doll plant for about six months. It was lush and green and growing well until about a month ago. I noticed leaves falling off the branches. After a close inspection, I noticed pale, brown almost cream-colored dots on the leaves. The dots are about a millimeter in length. There is a white fungus where some of the branches have fallen off. It’s in a well-lit area and I am spraying it with water every other day. I would be grateful for any light you can shed on my problem. (e-mail reference)
A: It sounds as if the plant has a bad infestation of mealybugs and some species of scale. Based on what is allowed in your country, I would suggest visiting a garden shop to see if they have the appropriate insecticide to control these pests. If the infestation has progressed too far, it may be too late to save the plant. Don't delay in taking some kind of remedial action.
A: Norfolk Island Pines are native to Hawaii, which is a big clue. I have seen them fail where such care was given in homes on the mainland. I’ve also seen them thrive where they are not cared for in any particular manner. What is the secret to growing them successfully? Other than good cultural practices, the luck of the draw!
A: The book I think I mentioned was “Square Foot Gardening” by Mel Bartholomew.
Q: I've written to you before and gotten some very good advice. I need some more! I've had a philodendron for eight to 10 years. The plant has been repotted into larger pots three times. It has done remarkably well during the years. I have it in a south window, keep track of watering, keep it trimmed and only use rainwater or melted snow. For the past two weeks, I get a moldy odor from the plant. It sits right next to my recliner, so I get a whiff of that smell occasionally. My husband says I'm watering it too much, but I usually wait 18 to 20 days between watering. The last repotting took place about five years ago. I used Miracle-Gro potting soil and fertilize the plant about twice a year using Miracid, which I've heard is no longer available. Is it time to repot again? Does dirt get old? Any help will be greatly appreciated. (Bordulac, N.D.)
A: You could have two potential causes for the unwanted odor. It could come from the soil being too old or, more likely, the soil being in a container that doesn't have good drainage. If that is the case, what you are smelling is an anaerobic condition in the lower part of the soil. This condition definitely would produce a moldy smell. Either way, I suggest that you repot with fresh soil and use a container that is free draining. As you water the plant after the repotting, dump off the excess water that drains into the saucer about 10 to 20 minutes later. I also would suggest repotting on an annual basis rather than every five years because the soil compacts from watering. This compresses the macropores in the soil to (if you are interested!) micropores. Micropores are less able to hold a balance of air/water that is odor-free. Thank you for the kind words. I'm glad my past advice was good for you!
Q: I have been growing beautiful houseplants for many years. I add buttermilk to the soil to provide nutrients for healthy plant growth. In the past, you have written that practices such as this are just so much hokum, but I have had success using buttermilk. Your comments please. (e-mail reference)
A: It is hard to argue against success, that's for sure! Nothing I tell you will change your mind or practices. However, you have stimulated me to do a little investigating as to what buttermilk contains (I used to drink it as a kid, influenced by my grandmother Smith). Dairy products are rich in protein, which makes them a source of nitrogen. Being in the protein, the nitrogen slowly will become available to the plants as the proteins decompose and then provide a mild stimulant for plant growth. In essence, your use of buttermilk for this purpose is better than nothing. However, is it better than using the right commercial fertilizer? I doubt it because using buttermilk is a waste of good food intended for human consumption. I believe that the right commercial fertilizer, applied at the right time and in the correct concentrations, would do more for the plants and less expensively than the buttermilk treatment. These are my comments!
Q: My grandmother gave me some of her beautiful houseplants because she was having greater difficulty taking care of them. She claimed the secret of her success was adding spent coffee grounds to the plants three or four times a year. She worked the grounds into the upper parts of the soil. While I love my grandmother, I think this is a little weird. I have never heard of doing this. Can you advise? (e-mail reference)
A: Coffee grounds have been one of the staples of the organic gardener's compost pile for a long time. I dump my cold coffee on some of the houseplants in our office complex, but I don’t see a response one way or the other. Most sources of organic matter, such as coffee grounds, do contain some trace levels of nutrients that a plant can use. Research shows that coffee grounds can have widely varying effects on plants. Some of the effects are beneficial and some toxic. Fresh grounds (cooled and just hours old) may cause a nitrogen tie-up until soil microbes can break down the structure of the grounds somewhat. This is a subject that could drag on in answering, but let me end by saying that what your grandmother did probably had some beneficial effects on her particular selection of houseplants. She might have been a light coffee drinker and had the native wisdom to not overdo her applications. The minor acidifying effect of mixing the grounds into the soil may have helped make some of the metallic nutrients, such as iron, more available for use by the plants. You don't need to use coffee grounds to be successful. I assure you there are plenty of good commercial products and books that can guide you to taking good care of the plants. Go to my site atfor information on houseplant culture.
Q: Hello father! Do you have any recommendations for a beautiful, fairly low-maintenance flower or plant that would make a nice addition to a small apartment? The apartment receives a moderate amount of light, but has very little windowsill space. I inherited a beautiful flower vase that I would like to use. Any thoughts? Please let me know! Love, Lee Smith (e-mail reference)
A: Hi, Lee! I'll be darned, a houseplant question from my son in Boston! If it is a flower vase with no drainage holes, you will have a problem. The soil eventually will sour from anaerobic conditions and end up killing the plant. If you can use the vase as a pot holder with a plant in it, then there are plenty of plants to consider. Because of the low-light situation you are in, flowering plants would be a poor long-term investment. With foliage plants, you would have a better chance of success if you added some fluorescent light or a plant light that you could set on a timer to run for 12 hours per day. Here is a short list of some of the toughest houseplants that even will thrive on benign neglect: corn plant (dracena); Chinese evergreen (aglaonema); piggyback plant (tolmiea); dumbcane (dieffenbachia); snake plant, which also is known as mother-in-law’s tongue (sansevieria); and spider plant (chlorophytum), which is best used as a hanging basket plant in the window. All of these will survive and, in fact, do quite well in subdued light, as long as they are not overwatered. That is the biggest killer of houseplants. Your local florist should have some of these common and durable plants. Love, Dad.
Q: I'm devastated and sad that my crown of thorns has died after having it for seven years. It bloomed and sprouted small branches, but then the branches and the mother stem died. I think I overwatered it because of my worries that it wasn't getting enough. I still have the roots. What do you think I should do? (e-mail reference)
A: Being a succulent, this plant does not require much water, especially during the winter months. Then again, the plant may have entered into a winter resting (dormancy) mode. If that is the case, check the stems to see if there is any green, cambial tissue beneath the bark. If there is, then the plant likely will releaf for you sometime later this winter or early spring. Make sure it has plenty of light, allow the top inch of soil to dry before watering and make sure it is in a free-draining container. If you had the plant for seven years, it must be quite large, so it may need pruning. Right now, I would make sure that you have it in the right location and when you think it needs water, wait at least another day before watering. Plants can recover easier from too little water than too much.
Q: I have a question about my indoor orange tree. We purchased the tree from a local grocery store. It looked very healthy and had lots of leaves. We were very happy with the tree, but then the leaves started to fall off. Upon closer examination, I noticed it had little, reddish bugs on it. I misted the tree with diluted dish soap to kill the little beasts, but it didn’t work, even after several attempts. I then purchased a new pot and dirt and did a major transplant. I broke up the dirt that was attached to the roots and shook off what was left. However, all the leaves fell off within a day or so! Now it looks as though it has new leaf buds. Is this a common problem with this kind of plant? How do we keep the tree healthy and happy? Does it require any type of fertilizer or pruning? Does it need direct sunlight? (e-mail reference)
A: You did the right thing when you repotted and added fresh soil. Don't overwater or fertilize to excess. When in doubt, use less fertilizer, not more. Here are two sites with information on how to take care of houseplants: http://www.ag.ndsu.edu/pubs/plantsci/landscap/pp744w.htm and http://www.ag.ndsu.edu/pubs/plantsci/landscap/h1260.pdf.
Q: I found your Web site during a search and am hoping you can give me some advice about my jade plant. It's around 15 years old. Since this summer, some of its new leaves are growing weirdly. It is as if something is gnawing on the leaves. Most of the weird leaves look chewed in the center, making the leaf a figure eight or hourglass shape. There doesn't seem to be any visible bugs crawling on it, but there is sometimes a small line of bumps or a scar on the underside of the leaves. I put the plant outside during the summer, so I am afraid it could have picked up something while out there. Thanks in advance! (e-mail reference)
A: Get a reading or magnifying glass and look closely on the stems of your plant because something apparently is enjoying them as a meal. Don't just concentrate on the newly opened leaves. Look on the underside of the older leaves and along the stems as well. It could be that you have a scale infestation that needs to be eliminated or the destruction will get worse.
Q: I had two healthy plants on my deck this summer, but they are not doing well indoors. The miniature orange tree is dropping leaves consistently and there appears to be no new growth. There are white spots on the leaves. The hibiscus leaves are yellow and falling off. There are some webs present at the base of some of the leaf stems. How can I correct these situations? (e-mail reference)
A: Get plant lights for both. Keep the lights on for about 13 hours a day. Keep the plants away from forced air heating vents, mist frequently with distilled water and avoid drafts from doors opening to the outside. Leaf drop and cessation of growth are normal, so be patient. New growth adapted to the indoor environment should appear shortly. If misting does not eliminate or at least reduce the spider mite infestation on the hibiscus, get some of Schultz's Fungicide 3, which is a neem tree product that has fungicidal, miticidal and insecticidal activity.
Q: Can you advise me on how often to water a China doll plant I just purchased? My plant has been dropping leaves at night. My daughter thinks I’m not watering the plant enough. I have the plant sitting where it receives afternoon sun for a couple of hours a day. I only use heat to warm up the house in the morning (propane).We have spider mites in our house, so I put granules on the plant. Was that the wrong thing to do? (e-mail reference)
A: China doll is a fussy plant. It didn't like being taken from the florist shop. It absolutely doesn't tolerate cigarette smoke or inconsistent watering. Allow the soil to dry between watering. Overwatering will result in the leaves turning black and dropping off. Underwatering will cause the leaves to turn crisp and eventually drop off. This plant also is susceptible to mealy bugs and spider mites. The best way to control these pests is to mist the plant regularly with tepid water. Make sure the plant gets as much winter sunshine as possible.
Q: We have a few stalks of lucky bamboo in our house. The stalks have grown a little out of control. How do I prune them without killing the bamboo? Can I replant the trimmed stalks? The plant is in water. Any help will be appreciated. (e-mail reference)
A: You should be able cut back the stalks and root the cut pieces.
Q: I enjoy reading through the advice you have given others on your Web site. I have two crotons at work. I have moved to a new desk that has lots of bright light, so the leaves are taking off. There is a lot of vigorous growth and the leaves are five times as large as the existing leaves underneath the plant. I'm happy with this, but the new leaves do not have the tricolor effect that the leaves on the plant had when I purchased it. How do I get the plants to go from green to the red/yellow/green hues it used to have? (e-mail reference)
A: Try backing off on the direct sunlight by about 50 percent. The different colors should return after that. Crotons are tropical subcanopy plants that can get by with some direct or mottled light, but when given a generous amount, will tend to fade in color.
Q: I have a fiddle leaf that I have had for many years in the same pot. I would like to move the tree to a larger pot and possibly tie the branches in a way to help them from tipping over. Do you have any suggestions on how to relocate the tree in a new pot? (e-mail reference)
A: Do some pruning to cut down on damage to the branches. Then lift or knock the plant out of the pot and then plant the tree in a larger pot using fresh potting soil. It is a piece of cake.
Q: A friend of mine gave me a leaf of a plant she had. She instructed me to stick it in dirt so it would grow. The plant has done extremely well, but I don't know what it is! She told me she thought it was a cathedral plant, but all my searches for such a plant have come up empty. The plant reminds me of a Christmas cactus, but instead it has long "branches." From the branches come leaves that are long and sort of notched, such as a segment of a Christmas cactus leaf. It's supposed to bloom, but mine has not. I don't remember what kind of flower it's supposed to have, but I think she told me the flower is supposed to come off the leaf. If you could give me any ideas as to what this plant might be, I'd really appreciate it! It appears to have spider mites. I have used a cotton ball and some rubbing alcohol to remove them, but now they are back. (e-mail reference)
A: This sounds like a close relative to the Christmas cactus, which is epiphyllium, but I cannot be sure. Spider mites are best controlled with a blast of cool water because they hate it. After the weather gets nice for the season, summer the plant outdoors to allow natural elements to get to it. Summer it on the north side of your house.
Q: My vine cuttings have rooted. How do I make sure when I transplant the vines into a pot that they will survive? I transplanted two of them, but the leaves dried up. What should I do? What is the best soil to use for this kind of transplant? (e-mail reference)
A: Freshly-rooted grape stems with leaves present are tender objects. There are a couple of things you can try to avoid so this won’t happen again. Slowly harden the rooted cuttings by reducing the amount of water for three to four weeks. Transplant and cover the vines with shade cloth and a functioning mist system to keep the humidity high. Allow the cuttings to remain where they are until fall. At that time, gradually expose them to colder temperatures until the vines go dormant. You can try transplanting again under the present conditions, but do so at the end of the day, just before daylight ends, or on a cloudy day. Be sure the vines don't get direct sun and keep them misted. In every instance (except allowing the cuttings to remain until fall), try to reduce the air temperature to toughen the plants before transplanting
Q: I transplanted a cutting from my prayer plant, but the leaves on my new plant are curled. Could you tell me what's wrong and what I can do to correct the problem? (e-mail reference)
A: Get a small, clear plastic bag and cover the plant after watering. This will keep the humidity high around the plant and keep it from wilting. Do this for two to three weeks, then gradually uncover it until you can remove the cover without any wilting taking place.
Q: I found an aloe plant in the garbage can of our apartment building. It looks like it might survive, so I rescued it, but I'm not sure what to do with it. I found your Web site while looking for some answers. I'm hoping you can help me. It is in a fairly small pot. The stalk grows out of it for about 6 inches before there are leaves. The whole plant is about 30 inches tall. The leaves look healthy, but are damaged from being thrown out. A few of them have black spots, which I plan on cutting off. It topples over unless it's leaning against something. If I plant it in a bigger pot, should I leave the bare stalk or should I plant it up to where the leaves start? What else should I do or is this a lost cause? (e-mail reference)
A: Not a lost cause at all. Repot in a larger pot. Set the plant in the soil right up to the base of the leaves. Give it as much direct sunlight as possible without burning it and don't overwater.
Q: I have a clover plant I love. I am having problems with aphids and white bugs. What can I do to get rid of this problem? Would using a soap-and-water spray work? I have tried using Schultz bug spray, but it seems to kill the plant. (e-mail reference)
A: Try an insecticidal soap. It has the right formulation to kill bugs on houseplants, but will not damage the plant.
Q: I would like the names of different types of plants that can grow or survive with the roots emerged in water. I want to take a large, clear vase and decorate it with rocks and sea shells at the bottom, put a couple of tropical fish in it and have the plant growing out of the vase. (e-mail reference)
A: Many plants will do fine in a water medium. The water needs to be changed or aerated on a regular basis to keep toxins from building up. Of course, nutrients will need to be added on a spoon-feeding basis to keep the system going for any significant period. I've seen bamboo, African violets, spider plants, lilies, avocados and more thriving with their roots in water and maintained properly. Other than cacti and succulents, the choice is yours!
Q: I have a rubber tree that was doing great until I overwatered it. Now half of the leaves have fallen off. There are new ones growing, but it doesn't look nice without the rest of the leaves. If I cut it back, will it start over or kill it? Also, I have many plantain and wild violets in my grass. I know that I'm supposed to use Trimec, but my dog and cat love to eat grass. Is there a way to spray my yard without making my animals sick? Will Trimec get rid of plantain and clover? Thanks so much. (Jamestown, N.D.)
A: If you cut back the dead parts of the leafless branches and stems, it will not hurt the plant. Allow anything that has leaves remaining or coming out to stay. If it looks too weird for your taste, dump it and begin again, but retain the lesson learned. Trimec will get rid of most broadleaf weeds in your lawn, but it should be sprayed carefully where the weeds are visibly present. It is toxic to warm-blooded animals, so you should keep your animals off the lawn for several days. Follow label directions in using this or any pesticide.
Q: My daughter bought a dwarf orange tree a few years ago. It has been growing very well. We’ve searched the Internet looking for general care and pruning tips, but have not found anything except to water it when the soil is dry and to use sandy soil. It has a year to go before it is supposed to bear fruit. We have it staked to keep it upright. Should it be pruned? If so, how much do you cut it back? (Eagle Bend, Minn.)
A: Prune the tree and get more light to it by summering it outdoors, using artificial light during the winter or both. It shouldn't be spindly, which is the result of too low a light intensity and duration.
Q: I have a bamboo plant that sits in water under florescent light. For some reason, it's starting to turn a light green and the leaves are dying at the end. What am I doing wrong? I tried Miracle-Gro, but the water turned black. I promptly stopped using Miracle-Gro and replaced the water. The plants and the glass containers are getting a hard, white crust. I can't believe I am killing something as simple as a bamboo plant. If there was a plant jail, I would go. (e-mail reference)
A: Here is your pass out of jail. Purchase some potting soil and plant the bamboo in a well-draining container. Everything should be fine after that. I don't want a nice lady, such as you, spending any time in jail, especially for a bamboo!
Q: I have an aloe plant that I had to repot during the summer. It appears that fungus gnats were in the soil and infested all the plants in my office. I tried several ways of getting rid of the bugs. I ended up throwing the soil out and putting the aloe plant in water, which got rid of the pests. However, I need to put the plant back in soil, but I am gun-shy about the potting soil. The potting soil remained in my truck for about a week in below-zero temperatures. If there were any fungus gnat eggs in the soil, would they have survived the freezing temperatures? (e-mail reference)
A: Where are you getting this potting soil? Most potting soil on the retail market is pasteurized or sterilized. Freezing temperatures will take care of any adults, but as for the eggs, I wouldn't bet the farm on it. If you must use the soil from the back of the truck, microwave it first for about two minutes in an open bag. It will not smell nice, but that should take care of anything that might hatch out. Go to www.ext.nodak.edu/extpubs/plantsci/landscap/pp744w.htm for complete information on this procedure, along with other tips for solving houseplant problems.
Q: Is softened water bad for my houseplants? (e-mail reference)
A: Softened water uses sodium ion to replace calcium ion in the water supply. With time, it will kill just about any houseplant. It is better to use distilled or unsoftened water.
Q: I have several aloe vera plants that I’ve been growing for more than five years. They have done quite well, but the plants have developed strange black spots. The spots seem to be more concentrated in one bunch. I thought my kids may have overwatered, but the soil feels fine. What do the black spots mean, and are my precious plants dying? What can I do? (e-mail reference)
A: It is not a good sign if an aloe plant develops black spots. They probably have been overwatered, which is something that can be changed very easily. I would suggest that you take some offsets or divisions from the healthy parts of the plants and propagate them. For techniques on this, go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1257.pdff to download the publication I have on home propagation techniques. Take the cuttings or divisions and allow them to dry for a few days before attempting to root them. This will cut down on the possibility of the cuttings rotting. As for the spotted parts of the plant, allow the potting media to dry before watering again to see if they can recover. Don't be surprised if they don't. Once a fungus sets in, it is difficult to control.
Q: How do you get rid of mold on the top layer of dirt on a houseplant? (e-mail reference)
A: The mold is harmless and will not cause problems. If it has been awhile since you repotted, this would be a good time to do so. If you are not interested in this, then get a small hand cultivator and break up the surface to improve air penetration.
Q: I’ve had a rubber plant since December 2004. My husband let half of it die, but I managed to bring it back. I left it outside and it got really cold. I brought it in the next morning, but the leaves felt funny and now all the lower leaves have turned brown and are shriveling. Some of the top leaves also are brownish looking. Is the whole plant dying or is it possible to save it? It was a plant from my dad's funeral, so I hope it is not too damaged. (e-mail reference)
A: The plant may be reacting to the cold temperature treatment without it being lethal. If there was no killing frost, then it may recover in six to nine weeks. Give it normal care and don't fertilize or give it too much water. If the main stems turn mushy, then it is a goner and should be dumped.
Q: I have an indoor China doll that I've had for a couple of years. It has started to get "cotton-like" spots on the leaves and joints of the branches. I really don't want to loose it or have it spread to the other plants in my house. Can you tell me what it is and how to treat it? (e-mail reference)
A: Those cottony spots could very well be cottony cushion scale. If their numbers are small, you can swab them off with an insecticidal soap or alcohol-dipped cotton swab. If the numbers are too high, then you need to turn to a systemic insecticide, which is potent and has collateral effects on some plants.
Q: My mother and I have a lucky bamboo that was given to her a year ago. Since that time, I have changed the water and washed the stones before repotting the plant. The bamboo is in a clear glass container and we are trying to use pure water, rather than tap. The problem is that every week after the water has been changed, the plant or the water starts to stink. What is going on? Can I transplant the lucky bamboo to potting soil instead of using stones? (e-mail reference)
A: Lucky bamboo is putting products of photosynthesis into the water through the roots. Get it moved into some potting soil. If you aerated the water, which is usually a pain in the neck to do for just one plant, you wouldn't have the smell problem.
Q: Four of us work in a tiny office without much ventilation (fresh air). We also lack any source of outdoor light. What would be the best plant to place in our office (and how many plants) to generate some oxygen? (e-mail reference)
A: Good question! There are a number of plants that can fill the bill, such as Norfolk Island pine, spider plant, wandering Jew, pothos (“Devil’s Ivy”), peace lily (Spathiphyllum), and Dallas or Boston fern. The Dallas fern is the tougher of the two, if the plant is neglected.
Q: I have an indoor plant that I was told is a corn plant when it was given to me. However, it doesn’t look like the pictures that I have seen of corn plants. My plant has leaves like a corn plant that would grow in a field and are a solid, dark green color. Recently, when it was moved into my house, some of the leaves turned black and began curling. They don’t appear to be dying, but are curling under and not staying wide. I have no idea what the problem is. I can’t find the proper care because I can’t find the proper name of the plant to match what it looks like. (e-mail reference)
A: The corn plant is known botanically as Dracaena species, of which there are many! Most people go for the exotic types, such as a variegated species. Yours is the unvariegated form. Go to the following Web site to see a form that resembles yours: www.desert-tropicals.com/Plants/Agavaceae/Dracaena_fragrans.html. Then go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1260.pdf for complete information on the care of houseplants.
Q: I just happened across your Web site while researching a problem I am encountering with an indoor, miniature orange plant. I inherited the plant about two years ago and it is flourishing. My only problem is that it produces so much sap that it is ruining my house. There is a layer of tacky, clear residue in a 6-foot circle around the tree. What is causing this and can I do anything to limit it? (e-mail reference)
A: If you look closely, you will find aphids taking up residency or spider mites. They are about the size of a period in a sentence. Both pests will extract plant nutrients from the leaf and stem tissue, which then passes through their bodies as “honeydew,” making everything it falls on tacky. I would suggest moving it outdoors and giving the plant several hard sprays of water. This will dislodge these pests and may be sufficient so that the problem no longer exists. In addition, by summering it outdoors, there is a chance that natural predators will find the pests and wipe out the rest for you. As a final solution, you can try Orthene, which has miticide and insecticidal activity and is both a contact and system material.
Q: I have an approximately 25- to 30-year-old snake plant that I inherited from my mother. I am not sure what species it is, but it does not have the yellow rim around its leaves. My question is about the yellowing that has occurred in the last few days at the core of the stalk. The inner 5 inches of stalks are yellowing while the rest of the stalks are green and healthy looking. I am wondering about root damage or other problems. I have to admit, I never have been that great at watering it regularly. It has sometimes gone weeks to a month without being watered. I never have had problems with this plant before. I am wondering if the pot is too small or if there is a problem with the soil or drainage. I definitely do not want this plant to die. It has been around as long as I have. (e-mail reference)
A: You probably have some root rot taking place in a plant that old. Remove it from the pot and divide the crown. Get rid of anything that looks like it might even have a little rot. Take a couple of cuttings as well. The cuttings should be about 8 or 9 inches long. Stick them in a sand/peat mix and keep moist. In two months, a new plant will appear from the base and the cutting leaf itself eventually will deteriorate, which you can then dispose of. This gives you a little backup insurance in case something happens to the mother plant. Like any houseplant, don’t overwater, keep it in a container that is free-draining, and after watering, dump out the excess water.
Q: I have had my aloe vera plant for a few months. When I bought it, it was malnourished. I thought I could help it recover, so I started watering it once a week. A couple of weeks ago I noticed one of the leaves had turned brown at the stalk, so I removed it. Then all the leaves began to grow outward. I thought the leaves were growing outward because it needed to be replanted. As I began to replant it, I noticed that another leaf had turned brown, so I pulled it off. When I did, half of the bottom stalk came off with it because it was rotten. In essence, my leaves are growing outward horizontally and the bottom half of the stalk has fallen off. Is there any way to save my plant? It is very near and dear to my heart. (e-mail reference)
A: Overwatering is the culprit, so back off. It will not reverse the rot that has taken place, but you can pick off the leaves from the stem and allow them to cure for a day and then repot in pasteurized, well-drained soil.
Q: In my kitchen near a northern exposure window, I have a very pretty, braided trunk Eugenia (Syzygium Paniculatum) mini tree. I have had it for several years and am training it into a nice topiary-style ball. I have two problems that may or may not be related. Although I never let it completely dry out (having learned the hard way), every couple of months it decides to drop about 30 percent of its leaves. The fallen leaves feel crisp. For the past few months, most if not all, the new leaf growth is covered with a clear, very sticky sap-type substance. I also noticed that the top edge of the clay pot in which it lives is also sappy and sticky. The plant never has done this before. I see this lovely plant every day and it gives me a great deal of pleasure. I would love to help it. Any diagnostic clues you can give me would be most welcome. (e-mail reference)
A: This cause is spider mite feeding. Look closely at the plant with a reading (magnifying) glass if necessary. You should see their little webbing or crawlers on the foliage. They insert their stylets into the leaf tissue and start sucking out the liquid. The liquid passes through their bodies and becomes a sticky sap, which eventually causes the foliage to drop. Get a miticide at a local garden center and spray the plant. Mist the foliage on a regular basis or run the plant under a tepid shower every so often to help keep mites under control.
Q: Do you have any idea what would cause coleus leaves to dehydrate in the middle? The problem seems to start at the midrib (both sides) and work toward the edge of the leaves. The plants appeared healthy at purchase. (e-mail reference)
A: It sounds like it could be botrytis, a fungal disease brought on by too much water and high humidity. It is not unusual considering where coleus is planted, such as shaded locations where sunlight cannot dry the foliage quickly.
Q: I recently took a botany class and loved the experiments. Why do leaf cuttings take longer to produce new leaves than stem cuttings? (e-mail reference)
A: Energy reserves, more “horsepower” so to speak, to get production going at a faster rate.
Q: The other night I was looking over my plants and to my surprise, I saw a millipede in my coleus plant. The little bugger was crawling around in the soil. Can these critters harm my plants? Also, the soil that I use for all my plants is from Miracle-Gro. I noticed that in some of the soil there are little weeds. The weeds look like miniplants with two small leaves and a stem. Could these be weeds? (e-mail reference)
A: The millipede could have come from anywhere, including the potting soil. They feed on decaying organic matter, which should be abundant in the potting soil. If what you see coming up is not what you planted, then they are weeds. You might want to check with the company where you made the purchase and see if the staff have an explanation. Potting soil is supposed to be pasteurized, which means no insects or weeds popping up! You might take the pot with the weeds down to the store to show them, along with the remaining contents of the bag to get a refund or replacement.
Q: I want to grow a snowball bush from a cutting. To make a long story short, this would be a fourth-generation bush. I’m not sure how to get it going. Right now, it is sitting in water. Please help. (e-mail reference)
A: Softwood cuttings from all viburnum are rooted easily in a 50/50 sand/peat mixture. Take the cutting out of the water or get some fresh cuttings and reset them.
Q: The blooms are falling off the fuchsia my husband bought me. It is located in the shade on our front porch. The porch is enclosed, but has four big windows. The blooms that are falling off haven’t opened up. Can you please tell me what to do about this problem? (e-mail reference)
A: Fuchsia needs at least three things to look good. Fuchsia needs bright light with some direct sunlight for two to four hours a day. It also needs a cool environment and almost continuous fertilizing with a liquid flowering houseplant fertilizer. Lacking any one of these conditions can cause the flower petals to drop. My guess is that your front porch may be too warm or it fails to get direct sunlight that can reach the plant.
Q: What causes a clear gel substance to form on the leaves of some houseplants? How do I get rid of it? (e-mail reference)
A: What you are seeing is the excrement from aphids or spider mites on the plant stems or leaves. Wash the plant in a spray of tepid water or wipe off the surfaces with a wet cloth dipped in insecticidal soap.
Q: While visiting my daughter, I noticed what I think is scale (small, scabby-looking brown things concentrated on leaf bottoms with a few on the tops and lower stalk). These are in a large and otherwise healthy looking pittisporum. I roamed around your Web site and read the questions and answers, but I didn’t find a specific description of scale or how to get rid of it. Can you give me some advice or direct me to the proper Web site? (e-mail reference)
A: How negligent of me not to have more descriptive information on my Web site on one of my favorite plant pests, soft and armored scale! Soft scales usually are not a big horticultural problem because there are many natural controls that keep them in check, such as parasitic wasps and lacewing larvae. In addition, they can be checked in their progression by a hard rainfall or a good washing from a garden hose. Horticultural oils are among the most useful treatments of soft scales on outdoor and indoor plants. The armored scales, which is what you seem to be describing (the oyster-shell species), are equally susceptible to natural predators in the early stages of their lives and to horticultural oils as well. However, once the armor scales are in place, these pests become particularly difficult to eliminate or bring under control. If they are confined to just a few branches or leaves, it is best to prune those off and dispose of them. Then spray the rest of the plant. Spray the upper and lower foliage surfaces with just about any insecticide to take care of any immature crawlers that may be considering establishing a home on the plant. Some control can be obtained by scrubbing with a pot scrub brush to disrupt them from the stems and leaves. While pittosporum is a tough and durable species and probably can carry a few scale or mealybugs, which they seem to be more prone to, it is best to bring any recognizable pest under control as soon as possible with the least toxic method possible.
Q: In January, my mother came to visit and gave me some clippings from two of her plants that she thought were philodendrons. One of the plant clippings was cut where the stem came out of the dirt because she didn’t want the plant anymore. It turns out the cuttings are scindapsus. One is a marble queen and the other is a golden pothos. I have a lot of both. I kept them in water until I could buy some pots and soil. They grew roots by the time I got them potted. The marble queen is doing beautifully, but the pothos (the one she cut at the dirt to get rid of) is wilted. She had it growing up a stump of wood, which is what I’m doing with it. There are six clippings in the pot. Other than the wilting, I don’t see anything wrong with them. I don’t see a sign of black leg. A month ago I tried a rooting hormone. Of the six clippings, one is doing great. I water it when the top 1/2 inch of soil gets dry. I mist it occasionally and it sits in a south-facing room with all the other plants that I’ve had for years. I can’t figure out what is wrong with this plant. It’s been wilted for four months. Can you give me any ideas on what to do? I am very attached to my plants and I don’t want to lose it. (Courtenay, N.D.)
A: The wilting of a plant is an indication of insufficient water taken up by the root system or, in this case, the base part of the plant. I would suggest making a fresh cut at the base in case it has become partially sealed. Try misting the foliage or using a humidifier in the room where it is placed.
Q: I have a rubber plant that is about 7 feet tall. If I cut about 4 feet off the top and stick it in soil, will it root or die? (e-mail reference)
A: It will die. Four feet is too much to root. If you do an air-layer coming back about 12 inches from the top, it should root in about six weeks. You can then repot it, giving you another plant. You then can cut the mother plant back to the height you want.
Q: I recently potted my scindaspus aures in soil that I dislike. How I can get rid of the soil without harming the roots? (e-mail reference)
A: Carefully wash the soil off the roots and immediately repot with the desired soil.
Q: I recently purchased an aloe vera plant from a gardening center. This is the first aloe plant I have owned. Do I need to repot the plant? If so, do I separate the clusters when I put them in a larger pot and separate the root system or can I just loosen the soil from the current pot and place it in a larger pot? I also have read about taking sprouts and making a new plant. How do I do this? I also would like to use the aloe for medicinal purposes when the occasion arises. What pieces do I cut off for use and how do I cut them? (Grand Forks, N.D.)
A: You have purchased one of the easiest plants on the face of the earth to keep as a houseplant. Keep it in your kitchen or very near it because that is the place where you probably will need it if you are going to use it for medicinal purposes. If an accidental, minor burn should take place, cut off part of a leaf with a scissor or knife and rub it on the affected area. The juice from the leaf will provide instant relief and protect you from infection. Aloe vera plants thrive on being pot-bound. I’ve known aloe plants that never have been repotted in 10 or more years and are doing fine. They easily are propagated, as are other succulents. Divide with a knife one of the offsets and let it cure in the air for a couple of days, then plant. Leaf cuttings also will work this way. Water liberally during the summer. During the winter, shut down the watering to about once or twice a month. That’s about all there is to growing this handy plant! Enjoy.
Q: Can a Madagascar dragon tree plant that is a houseplant be taken outside for the summer? I have had mine outside for about a week and now the leaves are turning white. Will it be OK or will it die? (e-mail reference)
A: It can be moved outdoors, but it can’t go from a 300 foot-candle light intensity to a 10,000 foot-candle intensity without some damage to its tissue. Place it outdoors after all danger of cold weather is past. Temperatures of just 50 degrees at night can cause problems with houseplants. That may have been what happened to your dragon tree. If the plant tissue did not freeze and the main stem still is firm, then there is a chance that it will recover in a few weeks. Just be patient and don’t treat it any differently than you normally would.
Q: I am interested in a recipe for a leaf cleaner/insecticidal soap mixture. How much dishwashing detergent should be mixed in the water? The mixture would not contain any insecticide, but I understand the combination of soap and water gets rid of insects. Another reader wrote of noticing tiny insects while watering a plant. When I water my plant, there are extremely tiny things that seem to be jumping around the soil. (e-mail reference)
A: Purchase insecticidal soap. Don’t try to make a concoction of your own because your formula could damage the plant. Insecticidal soap will not cause problems when used as directed. It contains no insecticide, just the necessary fatty acids that are plant protective and effective at desiccating the insects. I suggest wearing dishwashing gloves when using insecticidal soap. Those jumpers that you see when you water are known as springtails. Most feed on soil microbes, such as bacteria and mold, where high levels of organic matter are present in the potting soil mixture. They are more of a nuisance than anything else. Most people choose to live with them. Applying an insecticide gets most of them, but not all. If they really bother you, I suggest repotting with sterile or pasteurized potting soil and using a clean pot.
Q: I bought a dracaena “white jewel” a few months ago. It has done absolutely nothing! I’ve tried to alter the types of light and water, but nothing has happened. I repotted it a few months ago because I noticed the roots were still in the shape of the original pot. The only Web sites that have any information are written in European languages. I’d really like it to do something because it is a cute little plant. (e-mail reference)
A: The “white jewel” is a cultivar of the dracaena fragrans. The basic information on growing dracaena is what you will have to go by because there is nothing specifically written about the “white jewel” or any other cultivars other than descriptive appearance terms. Dracaena is a slow-growing plant. Any variegated cultivar that has a reduced level of chlorophyll in the foliage will be even slower growing. Fast growing houseplants drive their owners crazy with top-heavy growth and often have insect or disease problems. My advice is to enjoy this lovely plant in the temporary static state it presently is in. Rejoice when, in a few months, it produces some new growth. I assure you it will happen.
Q: I have ti plant cuttings that I partially put in water. The cuttings started to sprout, but do not have roots. I put plant food in the water and the cuttings became waterlogged. I put the cuttings in soil and I am hoping they will take root. How do I fix this problem? Should I order new cuttings? (e-mail reference)
A: You can grow ti (Cordyline spp.) plants in water, but the water needs to be free of fluoride and fertilizer. If grown in soil, the soil needs to be sterilized or pasteurized and without added fertilizer. Roots should form in about six weeks. Based on what you have told me, I would suggest ordering new cuttings and starting over.
Q: I have a question about dragon’s blood sedum. I found it in the Henry Fields catalog. I have some sedum that does well, but the catalog says it is “southern certified.” Does this mean it is only for southern climates? The catalog says it stands heat, drought and poor soil. (Bowman, N.D.)
A: Dragon’s blood sedum will grow nicely in Bowman. It will take heat, drought and cold temperatures. Unless we have record-setting low winter temperatures, with no snow cover, this cultivar of sedum should establish itself very nicely.
Q: We have four large sedum plants in our yard. They start out nice in the spring, but the base is so tight that about July the plants split down the middle and start to droop. I assume they are too big and need to be split. Can you tell me when to do this? Can I transplant the portion I remove? (e-mail reference)
A: Sedum will tolerate digging and splitting anytime during the growing season. The plant re-roots easily, so the worst gardener in the world can rebuild confidence just by sticking pieces of this plant in a high-sphagnum, peat-based soil that can be kept damp.
Q: I have a couple of philodendron plants that I keep at work. I’ve had one of the plants for a long time and it is doing great. I recently received the second plant as a gift. I have noticed some of the leaves are starting to get brown spots with yellow rings around the spots. I’ve also noticed black specks that I continue to wipe off, but the specks keep coming back. The specks don’t seem to be moving. I keep both plants on the same shelf. They get sunlight from a window, but not direct light. The temperature in the office is not too cold or hot and I water them a little every other day with bottled water. (e-mail reference)
A: It sounds like one of your plant has a fungal or bacterial disease. I would guess a leaf spot fungus. Without knowing exactly what it is, I would recommend using Schultz’s Fungicide 3 because it is a fungicide, insecticide and miticide. It is derived from a neem tree, so it is not toxic
Q: Is there any benefit to adding used coffee grounds to the soil? Do I need to stir in the soil or can I add the grounds to the top of the soil after the plant has been potted? Are there other vegetables that can benefit by adding coffee grounds? (e-mail reference)
A: Used coffee grounds improve soil tilth and provide a bank of trace elements. You can stir the grounds into the soil or add the grounds to the top of the soil. All veggies benefit from the addition of used coffee grounds.
Q: In 2001, we moved into a new office, so the manager’s wife brought in a plant cutting, placed it in the window sill and there it stayed for about 18 months. It never grew in size, but it did bloom. Even though that little stub never grew, it was very healthy looking. Every morning there was a swallow left in my coffee cup (no cream, no sugar), so I began to pour the leftover coffee in the plant. The little plant began to grow and now we have repotted it. We have grown six other plants from that once stubby little plant. The plant is beautiful and everyone comments on it as they walk into our office. We think the only reason it doesn’t look exactly like those in garden centers and florist shops is that ours likes coffee (no cream, no sugar). What is in coffee that would make the difference in growth? (e-mail reference)
A: Coffee is a rich source of most nutrients needed for plant growth, all in trace amounts. The fact that the coffee has gone through a hot-water treatment with the grounds causes the nutrients to leach into the liquid that we drink. Adding coffee to the soil on a regular basis provided nutrients for healthy growth.
Q: I purchased a musa plant from a supermarket, but there were no instructions with it. It seems happy at the moment. I am watering it and the plant has new leaves. Is there anything else I should be doing? I will begin to feed it in a couple of weeks. (e-mail reference)
A: A musa is the botanical description of a banana plant. I only can make general recommendations because I don’t know what species you have. Keep it warm, which means a temperature above 60 degrees during the winter months. Give it as much bright light as possible, even some direct sunlight. Keep the soil moist and frequently mist the leaves. Repot when necessary during the spring or summer. In essence, treat the plant as if it were growing in a tropical environment. Generally, if these species produce fruit, it is inedible.
Q: I am looking for a nice medium-sized plant that I can put in my bedroom. My bedroom gets a good amount of sun. Do you have any recommendations? Any suggestions on how to keep a bamboo plant healthy? (e-mail reference)
A: I can suggest growing many different houseplants, but I would rather that you make the decision. Go to www.ext.nodak.edu/extpubs/plantsci/landscap/h1123w.htm or
www.ext.nodak.edu/extpubs/plantsci/landscap/h1260w.htm for the information. Visit, download, read and enjoy!
Q: I would like to buy my sister an orchid and have it delivered to her house. What type is the easiest to grow? I found a great Web site that sells orchids at www.ontarioorchids.com/default.aspx. (e-mail reference)
A: The classic beginner orchid is the Phalaenopsis, which also is known as the moth orchid. It is a member of the Dendrobium group. I’m sure she will enjoy it!
Q: I have a philodendron that I recently transplanted. I’ve done it before without problems. Now the leaves are turning in and becoming a bright yellow. The soil seems dry, but I am afraid to water it because the symptoms are signs of overwatering. I cut off three leaves and now there are three more I need to cut. Do I keep cutting them off? (e-mail reference)
A: First, a mild scolding to you and others who choose to correspond with me. If you don’t put something related to the e-mail message in the subject heading, you stand a very good chance of being dumped along with the overwhelming spam that floods my address. Is the pot free- draining? Underwatering and overwatering can have the same symptoms. In addition, anaerobic conditions from having a nonfree-draining container can result in the same symptoms. You didn’t indicate if you set the plant back in the same location. Some plants are very sensitive to having their location moved and will respond with leaf discoloration and drop. I’d suggest you go to the following Web site for information on houseplants:
www.ext.nodak.edu/extpubs/plantsci/landscap/h1123w.htm. You also might want to check another publication on houseplants at www.ext.nodak.edu/extpubs/plantsci/landscap/h1260w.htm. I believe that some of the information in these publications will help you discover the cause of your plant’s decline.
Q: Two years ago, I got a healthy yucca plant. The bottom leaves started withering and turning yellow/brown. New leaves still were growing from the top, but the bottom ones were dying faster than the new ones were coming in. Last summer, I put the dead plant outside and a new shoot came out from the bottom and was doing very well. When winter came, I brought it in the house and now the bottom leaves again are starting to die. This year I got a plant that looks like it comes from a family similar to the yucca because it has large, wide leaves branching off the central stem. The same thing has started happening to the new plant. People at the nursery say it’s due to overwatering, but I haven’t watered the plants in months. Both plants get a good amount of indirect light from north-facing windows. Do you have any advice? (e-mail reference)
A: Have the interior air quality checked during winter. These plants are the miner’s canary because they tell you if something is wrong with the indoor environment, especially if you are not overwatering. That’s the best guess I can arrive at with the information provided.
Q: How do aloe plant leaves create a microclimate? (e-mail reference)
A: Size is what matters. When small, the environment influences the plant by killing or nourishing it. If the plant adapts to the ecosystem (assuming no outside human help), chances are good that it will survive if it is overlooked by herbivores or predatory insects. As the plant mines the nutrients and water from the soil matrix, it increases in size and vigor and is able to make and store food. As the plant size and vigor increase, the plant begins to affect the local or microclimate by spreading its foliage and cooling the soil. This creates a habitat that can help support other living organisms that could not have survived if that plant was not there. Parts of the plant will continue to increase in size and number and parts of it will die and drop off (as we humans lose hair from our heads). This decaying organic matter provides nutrients that may help support other forms of plant life. Aloe plants are unique in their leaf arrangement. The leaves capture rainwater, which can be used by small wildlife and insects. Again, a microclimate is created that was not there before the plant matured. In a nutshell, this is how an aloe or any other plant can create a microclimate. I hope this is what you were looking for.
Q: I wrote last year about an orchid problem I had. The leaves were shriveling and limp. It died. I was under the assumption that, since orchids love humidity and moisture, I should water it when the substrate is slightly dry. I have come to realize that the worst thing for orchids is overwatering. I’m also ashamed to admit that my husband uses the “nurture by neglect” method and has been able to keep his orchid alive for nearly a year. It even has a new leaf coming out. We have it a foot away from an east window in a cool (60 to 65 in winter) bathroom during the colder months and keep it in a three-season porch or outside during the warm months. It isn’t misted during the winter, but I sneak in a watering (not soaking) every month. The only water it gets in the summer is regular misting and an occasional rain. I hope this helps someone. (Aberdeen, S.D.)
A: Thanks for the information. I always enjoy getting information on horticultural stuff I know very little or nothing about. I’m sure what you said will be of some use to beginning orchid growers. Isn’t it irritating that sometimes people who seem disinterested in growing plants have the best luck? Thanks again!
Q: The zebra plant I am trying to find out about is the “aphelandra squarrosa.” (e-mail reference)
A: Aphelandra squarrosa has about the same requirements as another zebra plant, the calathea. Keep the potting soil constantly moist, but not soggy. Never allow it to dry out. Provide plenty of bright, but indirect, light, keep it warm (never below 60 degrees) and fertilize every other week. Keeping the humidity high around the plant also is key. Mist the plant, set it on a tray full of pebbles and water and use a humidifier. Any and possibly all of these ideas may be needed to keep your zebra plant looking as good as the day you acquired it.
Q: My son threw a sandal at my Yucca cane plant and broke the stem about a quarter inch from the dirt. What can I do to save the plant? It truly is a beautiful plant. (e-mail reference)
A: Make a clean cut to remove the top of the plant and stick the cutting in a rooting medium. The base also eventually should send up new shoots. In theory, you should get two plants out of this little accident! Go to my Web site at www.ext.nodak.edu/extpubs/plantsci/landscap/h1257w.htm to learn more about home propagation techniques.
Q: I received a zebra plant for Christmas. I would like to know how to take care of it. I’ve heard it is a difficult houseplant to grow, but mine seems to be doing well. (e-mail reference)
A: By zebra plant, I assume you mean calathea zebrina. They do not do well in direct sunlight, so it should be shaded continuously. Watering should be watched closely because the potting soil should not dry out. This group of plants is particular about humidity. Surround the plant with damp sphagnum peat on a tray of pebbles filled with water. That will help a lot. You also could purchase a humidifier for the room. The room temperature should not be allowed to go below 60 degrees. Fertilize only when the plant is showing active growth. Calathea zebrina make good terrarium or bottle plants.
Q: I have a surprising, but impressive situation with my dracaena reflexa (song of Jamaica, I believe). I stuck a cutting in water a couple of months ago (October) and never got around to planting it. It has been sitting on a poorly lit and insulated window sill all winter. I felt bad about it, but didn’t do anything. It grew roots in the water, put out one or two leaves and suddenly decided to produce fruit. The tip is generating cream-colored seeds, micro-flowers or something else. Should I plant it now? Can the seeds be planted? Can I save them? Is this common? (e-mail reference)
A: When plants are under stress, they often go into a “shocked” reproductive mode. The plant is “happy” with the care you are giving it and is remaining in a physiologically juvenile state (non-reproductive) because the conditions for vegetative growth are maintained beyond the optimal. That’s one possible explanation. It could be the plant has not accumulated enough carbs to go into a reproductive stage. This might sound like a contradiction, but the plant may be using up its reserves to perpetuate it by going into a reproductive state. Perhaps, based on the genetic factors for plant growth and reproduction, not all the “ingredients” for reproduction are in place. This doesn’t hold true 100 percent of the time. Almost nothing does in biology. There are predictions, expectations and exceptions. I often recommend “traumatic stimulation” on nonbearing apple trees, which is the driving of a straightedge spade into the ground around the canopy edge of the tree in several places. This shock treatment, a sudden reduction in root volume, starts the reproductive cycle.
Q: The leaves on my bamboo plant are becoming a lighter green. Can you tell me how to care for this plant? I also have a pothos gold that I keep in water. Can you give me any tips on keeping these plants healthy and growing? (e-mail reference)
A: I’m guessing that you are overwatering the bamboo plant during the winter months and possibly keeping it too warm. Bamboo does well in an unheated room during the winter, so try to locate it in the coolest place in your home and cut the watering in half. With the pothos gold, pot it with quality potting soil. Pothos gold is one of the most idiot-proof plants to grow indoors. Give it anywhere from 150 to 200 foot-candles of light or more, but not direct sunlight. Water it occasionally. Fertilize it during active growth. Pothos gold will lose its variegation if the light intensity is too low. We have had a couple growing in our office for more than 10 years. We cut them back and root the cuttings. The plants continue to grow even with our sometimes lack of care. In fact, a favorite Mexican restaurant has had one growing across the ceiling for years.
Q: I have a Spanish dagger tree in my home. I was told it was an indoor plant, but I’ve discovered it’s not. Many of the leaves have started turning yellow and dying. I thought the amount of light the plant receives might be the problem, so I recently installed a 75-watt grow light above the plant. I give it a half-gallon of water once a week. I don’t know about the watering (amount for pot size, frequency), the light or if it can live inside. (e-mail reference)
A: I think you mean the plant is a Spanish bayonet, which actually is the Yucca aloifolia. It is an attractive indoor plant. Keep in mind that environmentally and botanically speaking, there is no such thing as an “indoor plant,” only plants that we want to grow indoors. You did the right thing in providing supplemental light. Be conservative with watering during the winter months and liberal during the summer months. Like many houseplants, the Spanish bayonet will benefit from being summered outdoors. That is, if it doesn’t take a football center and fullback to move it for you! I think the reason you are losing some foliage, based on your description, is because of overwatering or the container is not freely draining. You can propagate this plant by cane cuttings or air layering. For propagation details, go to this Web site, www.ext.nodak.edu/extpubs/plantsci/landscap/h1257w.htm.
Q: I just bought a beautiful little schefflera. I would like to take it to my workplace, but I don’t have windows. I have a pleasant, open cubicle with a lot of overhead fluorescent light. Is that considered low, medium or bright, indirect light? I also would like to bring some ivy to my workplace, but I’m afraid that it needs natural light from a window. I have thriving pilea (aluminum plant, I think) that I’ve had at work for a few months. Should I get a plant spotlight for the umbrella plant or the ivy? I’ve looked at sites on the Web, but can’t seem to get an idea of what constitutes the different levels of light and how fluorescent office lights fit in.
A: Very good question. Thanks for asking it! Fluorescent lighting does a very good job of helping sustain our affection for houseplants. Proper lighting for indoor plants is best described as the product of intensity and duration. What this means is that the welfare of the plants is dependent upon not just the intensity of the light during the lighting period, but also the length of that lighting period. Tied in is the regularity of the lighting period. Lighting should not be sporadic. The age of the lighting units and the distance from the light source the plants are placed need to be considered. Plants will benefit if the lights are changed once a year and the plants are placed as close to the light energy source as practical. All of this said, offices typically make good locations for houseplants. In our office complex, we have a variety of houseplants growing. The plants range from Norfolk Island pines, all kinds of ivies, Christmas cactus and dracaena schefflera. With our fluorescent lighting system (the bulbs are changed only when they burn out), the plants get about 150 to 200 foot-candles of light. This is considered moderate lighting directly under the lights and at desktop level. The light fades to low light if the plant is stuck in a corner away from the lights. The foot-candles drop to 100 or less in the corner. Our lights burn from 7:30 a.m. to 5 p.m. five days a week and sometimes on weekends. All of the plants appear to be thriving. In a nutshell, with all of this background information being fed to you, any of the plants you are considering for your office should do well. Thanks for being a faithful reader of the Web site and for asking a good question. Nice to answer something different for a change!
Q: Last year I had a gorgeous shamrock flower. It became so large that I decided to transplant it into a larger pot. I used good garden soil that had peat moss added to it and used Miracle-Gro as a fertilizer. I squeezed the roots before I put the shamrock into the larger pot. After all that, the plant died. What did I do wrong? I plan to get another shamrock during the St. Patrick’s holiday season. (Valley City, N.D.)
A: You “squeezed the roots.” This species, in fact most species of houseplants, does not do well if its roots are squeezed or damaged in any way. Buy another plant for the St. Patrick’s holiday, but if transplanting is necessary, do so carefully. Keep the plant watered well in a free-draining container and give it plenty of light.
Q: I rescued a yucca plant from a friend’s place of business several months ago. It seemed to be doing well after repotting, but three weeks ago I noticed that several of the lower leaves had dried up. I pulled off the dead leaves and fed the plant. It seemed to be OK for a week, but now the same thing is happening. Even worse, the green leaves appear to be turning a spotty yellow. Any suggestions? (e-mail reference)
A: You may be overwatering or don’t have a free-draining container. Yucca plants are xeric in nature, so when we think they need water, nine out of 10 times we are wrong. It also could be that you have root rot. Knock the plant out of the container and check to be sure that the roots are still firm and healthy. Check my Web site on houseplant selection and care at www.ext.nodak.edu/extpubs/plantsci/landscap/h1260w.htm. Although yucca is not discussed specifically, there are guidelines for general houseplant care that may be of help.
Q: In response to a question, you said you would forward someone the “Home Propagation Techniques” booklet. If possible, could you send me the booklet? (e-mail reference)
A: I can do better than that! Here is a site where you can download the entire publication or just the part that is relevant to your interests, www.ext.nodak.edu/extpubs/plantsci/landscap/h1257w.htm
Q: I bought a palm tree houseplant a few days ago. It looked like it was in good condition. I replanted it in a plastic pot with a removable drain cover. I used Miracle-Gro soil. I noticed a day later that it was getting very dry and starting to shrivel. I looked closer and found some white fuzz on the soil. I scraped it off and removed the drain cover on the bottom. I put it in a more open container for fear of overwatering. I also added more soil. The plant is in an east-facing window, so it does get a considerable amount of light. There is a heat vent a few feet away, but it is not blowing on the plant. Can you please give me suggestions? I’m not sure what kind of palm it is. (e-mail reference)
A: Here are two of publications for you to read:
and www.ext.nodak.edu/extpubs/plantsci/landscap/pp744w.htm. In the publications, I have tried to cover as many aspects of houseplant growth, problems and care I can. If you are unable to find the answer after reading through the publications, get back to me and I’ll try to help you figure out what is going on.
Q: I have an aloe vera plant that looks strange. The plant looked normal until a few days ago, when this long thing shot up the middle of the plant. The mystery shoot now towers about a foot above the rest of the plant. Is it getting ready to bloom? Will it take over my house? (Pukwana, S.D.)
A: It is the flowering stalk. The aloe has accumulated enough energy to push itself into a reproductive or blooming cycle. It will not take over your house, so sit back and enjoy observing the plant attempting to perpetuate the species.
Q: I bought two China dolls about two months ago. They’ve been going down hill since. Both were on top of a console table in the window and I was regularly watering them twice a week. I was splitting a half-gallon milk container between the two. The leaves are quickly falling off. The leaves are yellowing and some have a slight brown coloring at the ends. I moved one plant out of the window and it’s doing better with less light, but it’s still losing leaves. I’ve stuck to the watering schedule. Each plant has lots of new growth at the top, some bright green and some reddish. I don’t know if I’m watering too much or too little or if this is a normal occurrence with this kind of tree. (e-mail reference)
A: You are very likely overwatering them. I suggest repotting the plants in a porous container that will allow free drainage. What you can do is follow a pot-in-a-pot system. Use the decorative container for appearances. Place the free-draining pot within the container on a bed of pebbles or styrofoam peanuts. Insert a piece of 2-inch PVC pipe to reach the bottom of the decorative container. Check about once a month with a yardstick to see if too much water is accumulating to the point that the interior pot is sitting in water. If so, take an aspirator and pump out the excess water. You can then cover the entire surface of both containers with a decorative moss, and simply pull it back to water when needed, but not on a set schedule. China doll plants need to dry down somewhat between waterings. In all probability, your plants will come back and be fine as far as appearance. These fussy plants don’t like drafts, too little light, don’t like to be moved or watered too much. Once you figure out the temperament and can maintain favorable conditions, the plants will be beautiful to behold!
Q: A colleague has given me an orchid that was going to be discarded because it had stopped blooming. I think it needs repotting because there are root shoots coming out from the top of the moss covering. These root shoots are climbing down the sides of the pot (they look pale green, and are wrinkled at the tips). The research I’ve come across says orchids prefer not to be repotted and like being crowded. This plant isn’t in bloom and one root shoot wraps down the pot about 8 inches, so I’m leaning towards repotting. I’ve no idea what type of orchid it is, but I think it may be a phalaenopsis. Do I need to give it fresh moss when replanting? Do I place the root shoots that are currently outside the pot into the new pot under the soil or do they stay aboveground? I read that it is best to clip the plant halfway back, but there’s a light green nub at the top (tip) of the stem above the dried nodes. Do they ever re-bloom at the exact point of where the last bloom was located?
A: I will admit that I’m not an expert at growing orchids, so the advice I’m about to give you will be from references. I’m going to assume it is a phalaenopsis or “moth orchid.” It likes growing in a low-light windowsill (except in a northern exposure) and enjoys warm household temperatures. To get it to bloom, a drop of 10 degrees between the day and night temperatures is needed. That temperature range is often difficult to attain in a typical household environment. You can pot the plant in a mixture of medium-fine bark, perlite and milled sphagnum moss. Keep the media moist, allowing it to dry slightly between waterings. To prevent bud blast (where the buds set and fall off before opening), keep the humidity high by frequently misting or setting the plant on a tray of pebbles filled with water. If the plant does flower, after the bloom fades and the end of the inflorescence is no longer green, cut it back to just above the second node from the bottom. Cutting it back may encourage a second bloom to develop in a short period of time. You can extend the blooming period of orchids or any flowering plant by keeping it in a cool and low-light intense location. If humidity maintenance is a problem, repot it in a plastic pot rather than a porous clay container. I hope this helps you!
Q: Does cutting the top of a plant permanently stop its growth? (e-mail reference)
A: It just removes the apical dominance exerted by the top bud and causes the plant to branch out.
Q: I’ve had an aloe vera plant for more a year. It was given to me in a plastic bag filled with water. I put the bag in a bowl when I got home. I never have replanted it because I’m afraid that it will die. I keep water in it all the time and it never has died. I would like to transplant it to a nice pot and have it get larger, but I’m not sure how. (e-mail reference)
A: I am surprised that the aloe has survived this long in only a water culture! Aloe and other succulents should be grown in containers and repotted when necessary, but only into the next nominally larger container. Be careful to adjust your cultural practices, especially watering, to reflect this move. Repotting, in most instances, is done close to spring. Supplementing with additional plant lights or providing adequate natural light usually will result in full-sized leaves. Being a succulent, it should be watered minimally in winter, kept in bright, indirect light, summered outdoors and watered moderately the rest of the year. Allow the potting soil to go dry between waterings.
Q: I repotted a plant that I expected to be root-bound, but was alarmed to see the roots extended only a few inches, not even to half the depth of the pot. It’s a plant that is more than a foot in circumference, but not leggy or compact. Why would the roots be so shallow? (e-mail reference)
A: There are a number of possibilities, such as lack of sufficient phosphorus, kept too wet, too low a light intensity or duration, stratified soil or a combination of problems. I suggest repotting with the appropriate soil, in a free-draining container and placing it in a bright, indirect light location. Water it moderately, allowing the soil surface to dry about an inch or so before re-watering.
Q: I know that nearly every houseplant needs a resting or dormant period, when watering and fertilizing frequency is reduced and the plant is placed in a cooler location to help it through its rest period. How long should we allow for this rest period before we put the plant back to its usual location and the fertilizing and watering schedule resumed? (e-mail reference)
A: About 60 to 90 days, depending on the plant. Some are very sensitive to this regime, others not. It requires observation skills on the part of the caretaker to respond to the nuances of change that some plants go through.
Q: I have had a China doll plant for two years. It has grown from 8 inches to 4 or 5 feet. Some of the shoots are leaning badly and are top heavy. I would like to trim it to allow it to become bushier, but I’m unsure how to do it. Do I cut the tops of each shoot? Can I cut 2 or 3 feet off each shoot? My mother-in-law gave it to me and I don’t want to kill it. I water it once a week. Would it require additional water after such a “hair cut?” (e-mail reference)
A: A China doll can be trimmed readily to increase bushiness. Make the cuts back to a lateral branch or stem, but don’t leave a stub. You don’t need to increase watering after trimming. In fact, watering on a set schedule is not encouraged, as conditions in a home change from one time of year to the next. The growth cycle of the plant also changes. Adjust watering to those conditions and you will not be in danger of overwatering.
Q: I need advice on how to store canna and glad bulbs this winter. I’m also wondering what I should look for when I buy a plant light. (Audubon, Minn.)
A: The corms should be dusted with sulfur and stored dry. You can use sphagnum peat if you wish. Put the bulbs in paper bags and store them in a cool (50 to 55 degrees), dry place. Plant lights are self-descriptive. Flowering plants such as African violets need more light than a philodendron, which is valued mostly for its foliage. Consequently, the philodendron could get along with light at a greater distance away, while the African violet would need to have the light source much closer. Fluorescent technology has come a long way in recent years. It boils down to what it is you want the light to do. Do you want the light to augment natural indoor lighting, produce flowering plants or grow vegetables?
Q: I’m afraid my rubber plant got too much of a cool draft. The leaves are now turning yellow and falling off. Is there any hope for my plant? (e-mail reference)
A: Yes, but you need to be patient and keep it out of drafts.
Q: My fuchsia is losing all its leaves and looks terrible. The greenhouse where it was purchased said it’s the weather and told me to cut it back. I think bugs. What is your thought? (Lisbon, N.D.)
A: It looks more like weather damage than an insect problem. Follow the advice from the greenhouse.
Q: I am trying to grow plants near my garage. I have plastic and rocks on it, but it gets quite wet. I want to plant something that has good color. (Gonvick, Minn.)
A: To help dry the soil, get rid of the plastic and rocks. You need to make your selections based on how much sun the area gets, what size plants you want and if you want flowering woody plants or flowering herbaceous plants.
Q: I have had my aloe a little over a year. It seems to be doing well and getting very large. Since last fall it has been getting white fuzzies on it that keep growing and hanging down. They feel sticky. I keep washing them off, but they keep forming. What are they and what can I do about it? (Bruce, S.D.)
A: It sounds like the plant has an infestation of mealybugs or cottony cushion scale. Make a solution of 50 percent rubbing alcohol in a pan large enough for you to invert the aerial part of the plant into the solution for about 10 seconds. Then let it air dry. That should take care of either of these characters.
Q: I have an aloe vera plant that I want to propagate. According to some literature, buds are present in the plant which will develop as plantlets. The only buds I can find come from the flowering stem. (e-mail reference)
A: The aloe is propagated via small offsets that are found at the base of the mother plant. The new rosettes are often attached to the parent by a short underground stem (stolon) and may already have some roots, which should be retained for propagation. Make sure the leaves have opened before detaching them from the mother plant to facilitate their rooting and further development.
Q: A co-worker has a ficus and rubber tree that they put outside. Do they need to take it inside on chilly evenings? I would think that a temperature below 50 degrees is not good for the plants. (e-mail reference)
A: Temperatures below 50 degrees are not good for tropical plants. Even though it is a pain, they need to be brought inside. In our area, I wouldn't move them outside until after Memorial Day!
Q: I used to own an aloe vera plant. It grew babies so I gave one to my mother. My plant developed a fungus which eventually killed it. The plant I gave my mother eventually had a baby which she gave to me. Within one week of repotting, the plant developed a light, fuzzy look over the top of the dirt. The plant has adequate drainage. I can’t figure out what is causing the fungus, let alone how to get rid of it. Can you shed some light on this problem? (E-mail reference)
A: Something has not been properly sanitized or sterilized. It could be the soil, container or the planting tools if any were used. It’s likely a saprophytic mold that is growing over the soil surface. When it gets to living plant tissue, it becomes a parasite which destroys the plant. Use only sterilized or pasteurized media in a clean, preferably new container. Do not over water or allow the water to stand in the saucer.
Q: How do I propagate a wandering Jew? The mother plant is huge and in a big pot along with a geranium. (Napoleon, N.D.)
A: It is very easy. Take a stem cutting, stick it in a peat-based media and keep it moist.
Q: I have been collecting cuttings and plants for years but I have a few questions. When growing an aloe, do you keep it root-bound for flowers and better growth or should you remove the pupsand and start fresh every few years? I have a few specimens from California that do extremely well root-bound, but I don’t want them to die. What are the best growing conditions for epiphyllum? I have cuttings that have been growing for two years but are starting to grow thin leaves, not the broad leaves like the parent plant. I have a starfish plant (Stapelia gigantea) that I managed to grow from a cutting, and it recently bloomed. Do you take care of it the same as a succulent? I found out it is part of the milkweed family so I’m very confused about how to take care of it. All of these plants are indoor and are located on the east side of the house near a window. (Minot, N.D.)
A: You have obviously developed cultural practices that allow you to maintain the aloe in a pot-bound fashion. Aloe and other succulents should be repotted only when necessary and then only into the next nominally larger container. Be careful to adjust your cultural practices, especially watering, to reflect this move. Repotting, in most instances, is done close to spring. Epiphyllous is closely related to Christmas cacti. It will respond to short day treatments to bloom. The undersized leaves could be caused by insufficient light at this stage of development. Try supplementing with additional plant lights to see if that doesn't increase their size. I hope you got the odorless species of Stapella gigantea or else I hope you have lost your sense of smell! It is a succulent and should be watered minimally in winter, kept in bright, indirect light, summered outdoors and watered moderately the rest of the year. Allow the potting soil to go dry between waterings.
Q: I bought several large houseplants 12 days ago. One the day I brought them home there was a terrible blizzard. Even though I bagged them tight with clear bags and warmed my van, they were still exposed to the cold. My yucca plant now has yellow leaves with brown tips. I watered them three days ago with filtered water. It is in the living room, which has bright indirect light.
My marginata dracaena has leaf drop and some tips shriveling up. I watered it three days ago and the topsoil feels dry at this time. It gets bright indirect light. My majesty palm has shriveling leaves but no leaf drop. I watered them three days ago and it is also located in the living room. My snake plants seem to be doing okay. I have windows all over the house so it's hard to find a place that is really nice and warm. My house temp stays around 68 to70 degrees. (E-mail reference)
A: It sounds like everything got a little nipped and will recover nicely when you summer them outdoors in about four months. Hold off on the watering during this transition period. Discount stores are famous for buying out a grower's current stock in Florida, Texas or Arizona and shipping them directly to their stores. They go from a semi-tropical, full sun environment to someone's house in the upper Midwest, and so are bound to show some "transition symptoms" such as you described. The plants will lose some foliage and yellow somewhat, but with a little patience and the proper care, such as not over-watering, they should all pull through for you. Next time tell them to double bag if the weather is unfriendly.
Q: I have a Madagascar palm in my living room that has west-facing windows. The palm is about 5 1/2 feet tall. Since we moved a year ago it has not grown or produced any new fronds. It looks like three very tall cacti growing in a pot. Does it need acidic plant food? What kind of soil does it prefer? Does it like to be root-bound or not? The plant has 3-inch spikes all over it and is horrible to transplant, so if it doesn't need it, I would rather not repot it. We've had this plant for over 15 years but in its current "ugly" state, my family is making noise about getting rid of it. (E-mail reference)
A: Your Madagascar palm is likely in a dormant stage right now. Since its native stomping grounds is Madagascar, it needs as much direct sunlight as you can give it. Because it is dormant, the plant’s water requirements are greatly reduced, needing only enough to keep it from shriveling up. When spring arrives, return to weekly watering but allow the soil to dry before watering again. It doesn't need fertilizer now, but should have a diluted shot of any houseplant fertilizer when new growth commences. I wouldn't repot this thing unless I had armor plates on all parts of my body! If the plant has become too ugly or too threatening, I would suggest taking cuttings from it and rooting those to start again.
Q: I have a question about my aloe vera plant that I am sure you can answer. I’ve had an aloe vera plant for several years. I put it in a larger pot a while back to give the roots more space. The spikes usually grow straight up, but on my plant only a few point upwards and the rest curve out over the edge of the pot then downward. Some are actually touching the table the plant is sitting on. Why don't they all grow upwards? (Detroit Lakes, Minn.)
A: That is simply the morphological characteristic of the plant. Every plant has a basic morphological form as it grows, develops and matures. With your aloe vera, the drooping foliage is a characteristic of maturity.
Q: My mom says that the brown leaf tips on my fuscia and other houseplants could be caused by the presence of fluoride in our water. What can I do to remove the fluoride? (E-mail reference)
A: Not much. I suggest using bottled or distilled water. Eventually, as new growth appears, the problem should disappear.
Q: I came across your web site and read everything I could find on sick shamrocks but didn't see one that applied to what seems to be wrong with my poor house plant. I have three pots of these and even the newest one (with pink flowers) has now developed this dreaded disease. I have some shamrocks that have developed spots. The plants are in good-sized pots and the newest one was moved into a larger pot on the day I brought it home. I had aphids about two years ago but there's not of trace of them now. The spots return even after I cut back all the foliage. I have several other houseplants but none of them seem to be affected by this blight. (E-mail reference)
A: The fact that you have had shamrocks for two years is a testament to your ability to grow houseplants with great competence! Most die after a few weeks. I am afraid that yours has a root borne disease that cannot be cured. The disease is apparently specific to the shamrock. You can try separating out any part of the root system that appears diseased and then repot. The chances it will recover are not good so I don't want to give you too much hope. Sorry.
Q: I don't know the name of my plants. I have replanted them and give them water once a week. I do not have them near a window because of the cold air drafts. The leaves do not have a healthy green look. What can I do to get nice healthy leaves? (E-mail reference)
A: Invest in some plant lights. Once you do that, it won’t take long before you see new healthy leaves emerging. Give them at least 12 hours of continuous light every day until you can move them close to a window.
Q: My co worker has a tall plant in our office that looks like a palm tree. We're not sure what it is, but she wants to cut it down because it has grown to the ceiling. What are our options for cutting it down and how do we do it? (E-mail reference)
A: If you cut a palm tree down, it is finished. If you cannot move it to another location where there is more room or give it to someone that has more room, then dump it. Palms are monocots with their growing points at the top of the plant. When that is removed, the plant is essentially killed.
Q: I have a hoya that I am caring for. I was told that it is a healthy plant and is approximately four or five years old. There are one or two yellow tipped leaves. Is it normal for it to have some white spots on the leaves? The spots look like sap. (Rapid City, S.D.)
A: A healthy hoya or wax plant should have dark green, uniformly colored leaves. The white spots could be scale insects and the yellow tipped leaves could be an overwatering problem.
Q: I am in search of the botanical name of the Irish tube houseplant. Any help or direction would be greatly appreciated. (E-mail reference)
A: Common names, you gotta love 'em! None of my references have anything close to this name. Sorry that I cannot help you.
Q: I bought a candlestick plant this past summer and grew it outside in a container. I wanted to bring it in for the winter, but thought I could take cuttings to start more plants. The first cutting I put in water died. Now I have cuttings that I dipped in root hormone and put directly into dirt. They have not died but their leaves are getting limp and turning yellow. I know nothing about this plant or how to care for it. There were vague planting instructions that came with the plant. The leaves are velvety and soft and seem to grow slowly. Can you grow this plant indoors or is it mainly for outdoors? (E-mail reference)
A: I need something more than the name candlestick plant. It is a common a name for way too many plants. Was there a botanical name on the tag? There should have been, or the grower should be scolded for not providing one. Generally, successful propagation takes place during the early spring or summer when the growth is most active.
Q: My fifth grade son has been assigned an elementary science project. He wants to do something with plants. We were wondering if germination techniques would be a good topic. Do you have any suggestions on experiments he could do with plants? (E-mail reference)
A: Some plant seeds need light for germination while others need darkness. He could take chamomile seed and sprinkle it on a flat of sterilized or pasteurized soil and take the same species of seed and bury it 1/4 to 1/2 inch into the soil. Place a fluorescent lamp with one cool white and one warm white bulb in the holder and suspend it about 12 inches above the flat. Keep the surface moist by misting. The uncovered seed should germinate well ahead of the covered seed. He could take any seed such as corn, beans or grass and sprinkle 10 seeds on three petri dishes with paper coffee filters in them that are saturated with some type of water. He could use distilled water, tap water and one molar solution of sodium chloride (table salt). To make a molar solution of sodium, take the atomic weight of the two elements of sodium and chlorine (23 + 35.5 = 58.5 grams). Take that figure, 58.5 grams or about 2 ounces and add it to one liter of water, which he can then add to the third petri dish. The sequence of germination should be distilled water, tap water and then the one molar solution of sodium chloride unless the tap water is very high in salts. Another possibility is to get a hold of an easy-to-root plant like coleus, forsythia or willow. Make six cuttings six inches long. Stick three in the sand with the top of the cutting facing up. Put the other three in the sand with the tops in the sand. You will need to keep them misted on a regular basis or at least keep the humidity high by placing them in a terrarium. In about four weeks the three normally planted cuttings will leaf-out and root. The others will do the same except they will be demonstrating what is called geotropism. The leaf tissue will be bending upward while the root tissue will be bending toward the earth. This is an example of negative geotropism, while the other is an example of positive geotropism. That should give him plenty of choices. Good luck!
Q: I have a wandering Jew plant and two Tahitian bridal veils. Are there any special directions for growing them? Occasionally the bridal veils develop an odor almost like cat urine. Could the odor be in the soil that the nursery used? (Glyndon, Minn.)
A: It has to be the soil from the nursery. They probably have cats they use for biological control of certain pests and the cats think the potting soil is for their use. Get pasteurized or sterile soil that is in a bag and hasn't been used by any cats! Both plants will benefit from strong, indirect light and even soil moisture maintenance. Both are tough and easy to grow, surviving on benign neglect. They also benefit from being moving outdoors during summer months.
Q: I have a Norfolk Island pine that is, it appears, two or three pines growing together in one pot. It was purchased that way a few years ago. The plant is ready to be moved to a larger container. Would this be a good time to separate the pines that are growing together? If it turns out that there is only one plant with multiple trunks coming up from under the soil, is it a matter of personal preference whether I leave them or clip them off, or would clipping off the smaller ones hurt the remaining larger one? Finally, if the smaller trunks are removed (either by separation or by clipping), should I still go ahead and move the main trunk into a larger container, or just repot it in the same container? (E-mail reference)
A: Norfolk Island pines don’t do well if things don't go exactly right. You have separate plants, which is a common sales practice with florists and nurseries. I would suggest separating them carefully and planting each one in its own container. Try to put them in a location where the conditions are as close to identical to the original as possible. With luck and if the plants are "in the mood" to being moved, you will have multiple Norfolk Island pines to enjoy well into the future.
Q: I have an aloe plant that is forming brown spots on it and drying up on the ends. Could I be underwatering it? (E-mail reference)
A: Sounds like you might be, but poor drainage and salt build up can result in the same symptoms.
Q: The leaves on my double impatience houseplant are curling. It gets plenty of water and does not have bugs. (Linton, N.D.)
A: Check the underside of the leaves for spider mite activity. If that isn't the problem, then it could be that you are over-watering the plant.
Q: Recently I have been finding gnats on my houseplants. Will the gnats harm my plants? How do I get rid of them? (E-mail reference)
A: Gnats are pests more to us than plants. They usually feed on decaying organic matter in the plant's container. They are easily killed with a houseplant spray that contains pyrethrum. Be persistent and you will soon have them under control.
Q: I noticed a yellow mold growing on my plant. I thought at the time that my 2-year-old daughter had dropped food or something on it. I scooped it out but then started to notice the same problem on other plants. I repotted the plants as soon as I noticed the mold. I have let my plants go dry thinking whatever it is it will dry out and go away but that doesn’t seem to work. (E-mail reference)
A: All I can tell you is that with sterilized or pasteurized potting soil and containers, this doesn't happen. It is a gross saprophyte that is not directly harmful to the plant. If you want to keep the same plants, go through the whole process again using new containers and pasteurized potting soil. Also, dip or wash the plants in a mild dishwashing solution.
Q: I have a dracaena marginata that is about 3 feet tall with a very thin cane. It appears to be healthy but it is not strong enough to stand upright alone. Should I use a stick to support it? (E-mail reference)
A: You can but I would look to the future and consider making that spindly cane into several propagules, which are called Ti trees. Cut the cane into 3 inch sections and insert the end closest to the roots into a rooting medium. Be sure to keep it moist. These pieces will eventually root, then you might get new, stronger growth coming from the mother plant. You might try providing that new growth with more light -- near an east or west window.
Q: Last week I checked my calla bulbs and found that they are beginning to grow. They have about one inch of new growth but seem to be quite dry. Should I pot them without water and leave them in the dark or should I just leave them as is? Because planting time is so far off, I'm thinking that the bulbs will wither and die. I also have two water lilies that are showing new growth and wonder if I should put them in water near the grow light? (Lisbon, N.D.)
A: Don't argue with the forces of nature. If they are showing signs of new growth, they are ready to be potted. Keep them watered and in adequate light until you are ready to move them outdoors this spring. Do likewise with your water lilies.
Q: Do you have any suggestions for dealing with powdery mildew on house plants? (Jamestown, N.D.)
A: Try moving the plants to an area with increased circulation, or simply turn on a fan. The mildew can be washed off with insecticidal soap. Even though this is for insect control, it also does a good job of cleaning off fungus. If both of these fail, then Schultz's Fungicide 3, a neem oil preparation. should do the trick.
Q: I had a sago palm growing indoor for about two years. Last summer it produced four or five new fronds (or whatever they are called) that were about 15 inches in length and looked healthy. Just as the needles started to unfurl, they dried up and died. About the same time some of the older fronds dried up (which I understand happens in order to provide food and energy for the new ones). Now this winter all of the rest of the older fronds dried up with no new growth coming up. Is this the end of my plant or might I still get some new growth? ( Bismarck, N.D.)
A: It doesn't sound good. I would suggest hanging on to the plant and try summering it outdoors to see if you get a reaction. As long as the stem is not mushy, it should be fine. If it becomes mushy, then go ahead and dump it.
Q: I have a very big problem with my crown of thorns plant. I've had this plant for many years but all of the sudden it wouldn’t bloom anymore. It then started to look sick so I cut off a stem and placed it in water. The main plant died not long after that and looked totally dry. The stems were deformed and twisted. I focused on the stem in the water and it was rooting so I thought it was fine. Then my boyfriend’s sister threw it in the garbage because there was no water. I retrieved it from the garbage and placed it in water again. I thought planting it in soil would help it but it looks like it's dying. I've put this plant through hell and I don't know what to do. (E-mail reference)
A: Try to get your rooted cutting in potting soil as soon as possible and do it carefully. Roots formed in water are usually more brittle than those formed in sand or other rooting media. It’s hard to say what killed your crown of thorns, but it could be overwatering. That is a common occurrence during the winter months. This is a plant that needs a sunny window, moderate watering from spring to autumn and sparse watering in between. Always let the media dry between watering. It should be repotted every other year. Lack of flowering is nothing to be concerned about. Plants expend quite a bit of energy during the reproductive cycle and often need a rest period for an extended time to rebuild carbohydrate reserves to get into the reproductive cycle again.
Q: I have two large containers with the most beautiful green foliage from cuttings taken from a kalancho plant. I have had this plant for more than three years. As it stopped blooming, I noticed root-like growth on the stems so I began to root them. They thrived and multiplied. After having them out on the deck last summer, I brought them inside and to my surprise buds are appearing. What I should do to encourage the new buds and bring them to bloom? When the plant dries its blossoms, how far down should the trimmings go? Thank you for your help and we enjoy your Q&A in our local paper. (Lisbon, N.D.)
A: Spring is the normal flowering time for this succulent. Don't cut flower buds back but do prune them after they have flowered. Do not over fertilize or over water. Allow the potting soil to dry between waterings. After flowering, like many house plants, it needs to be given a rest period for about a month in a windowsill that gets no direct sunlight. Allow the soil to go completely dry. Then move it back to a sunny location and resume normal watering. Thank you for the compliment about the column. Folks like you make it interesting with your questions.
Q: We have a Chinese evergreen in the hallway. The top leaves are green but every now and then one branch or bracket turns yellow. What causes this problem? (Valley City, N.D.)
A: Chinese evergreen, aglaonema commutatum, is a very durable and attractive houseplant. The yellowing appears to be nothing more than normal senescence (aging).
Q: I enjoy reading your column every week and always learn something new. I have a silver vase bromelaid that I need advice on. I only water the soil when it is very dry but I keep the vase constantly filled with water. I have one in a sunny south window and one in an east window. The ends of the leaves are turning brown and I'm worried about losing them. Can you tell me what I am doing wrong and how to care for them properly? They have gorgeous blooms when they reach maturity. (Woonsocket, S.D.)
A: Thank you for your very kind words! I try my best. Your term silver vase translates into a specific bromeliad for me. I think you mean the urn plant - Aechmea fasciata. You are correct in keeping the vase (the cup-like center of the plant) filled with water and I hope that you change it frequently to keep it from becoming stale and smelly. The leaf ends turning brown is an indication of the air being too dry (small wonder with our outside temperatures being what they are!). The plants should be misted often with distilled water that is at room temperature. It doesn't sound like you are overwatering and it appears you are giving them sufficient light, so dry air is my best guess.
Q: I have searched the Web for a prayer plant like mine and have been unsuccessful. My daughter forgot to water it so it died. It had grown to an incredible size. It was dark purple with little white flowers that popped up periodically. I don't know the scientific name of the plant. Almost every Web site with a photo shows a green prayer plant. (E-mail reference)
A: I don't know if I can really help, but I will try. The Maranta Massangeana has deep purple on the undersides of the leaves, with almost black markings about the midribs on the upper side of the leaf. The Merythroneura has purplish red undersides with many bright red lateral veins leading away from a light green midrib on the upper side. Finally, what you may be talking about is the M. tricolor - I have seen some with very dark upper leaf surfaces.
Q: I have a ficus that is 19 years old. It has been through a lot and now it has, on the back of most leaves, a small white spot where the leaf and stem start. When I scrape it off, it is black underneath. The white spot looks a little like a spider web. What can I spray it with? (E-mail reference)
A: It is likely scale which is getting started on your plant. I would suggest getting some rubbing alcohol and q-tips. Dip the end in the alcohol and rub the scale off completely. This is the most effective way of controlling this pest. Sprays are not effective as the pest’s covering can keep the insecticide from reaching the insect. Be thorough as one scale can easily multiply into hundreds in a very short time!
Q: I received a blooming shamrock as a gift. I have followed the directions exactly, which specify to water from the bottom up, put a plastic bag over the top and put under light in a warm place. Now I have mold growing on top of the pot. Can it survive? Should I throw out the growing medium and start from scratch? Can I take the bag off so the plant can dry out? Can mold spores get into the terra cotta pores? Should I get rid of that too? (E-mail reference)
A: If the mold is not on the plant, you have nothing to worry about - yet. Take the bag off and allow it to dry and it should be ok. Next time don't make the bag covering the pot so tight. The plant needs some ventilation to keep it from molding. You can scrape off what is growing there now, once it dries up somewhat.
Q: Can you tell me how to get rid of mold in the soil of a houseplant? (E-mail reference)
A: Either repot with fresh, pasteurized potting soil in a sterile pot, or simply scrape the mold off and work up the surface to encourage drying. Reduce watering frequency.
Q: I recently received a beautiful ornamental orange bush as a gift when my mother passed away. When it arrived from the florist, it was beautiful and appeared to be healthy. But almost overnight it started losing leaves and dropping fruit. How should it be cared for? How often should it be watered? Should it be in direct sunlight? There were no instructions with it and I hate losing such a beautiful plant. Can it be salvaged once it starts losing leaves, etc.? (E-mail reference)
A: Sometimes the gift plants one receives are too tender (not acclimated) for harsh household conditions. Keep in mind that most are grown in greenhouses where the humidity and temperature are carefully regulated along with the intensity and duration of the light they receive. Being put into a home where the humidity hovers around 10-15 percent is a major environmental shift for such plants. Your best bet is to allow nature to take it's course and eventually all the leaves will fall off. Then water enough to just keep the potting soil moist and not allow it to dry out completely. Keep it in a sunny window or under a plant light. New leaves should start emerging in about 6 - 8 weeks. This new growth will be acclimated to your household conditions and should thrive, produce flowers and fruit for you within another year.
Q: Perhaps you can help me figure out what is wrong with my (indoor) ficus. The leaves are falling off at an alarming rate. The newly forming leaf buds are often dry as well although the soil is quite moist. Often the falling leaves have dry patches on otherwise healthy looking green leaves. The plant has not been moved nor have any other changes been made. Is it possible that the pot is too small or that the tree lacks nutrients? For a plant about 4- feet tall, what typical pot diameter should I use? How often should the plant be watered? (E-mail reference)
A: You are likely overwatering the plant, as leaf fall is a typical symptom of this problem. Allow the upper half of the potting soil mix to dry before watering again. You needn't worry about the container size. As long as it is big enough to provide adequate support for the plant and it isn't a problem for you to move it when necessary. Generally, this species seems to thrive in a slightly over-crowded pot. I wouldn't repot until some root started emerging from the drainage hole and then just move it up to the next nominal size pot.
Q: I have a hoya plant that appears very healthy. It keeps getting buds but they turn yellow at the early stage and drop off. I have it in a south window and do not water until the soil feels dry. I do mist it occasionally because the house seems dry in winter months. How can I keep the buds from falling? (E-mail reference)
A: I would suggest misting daily to see if that helps.
Q: We started a remodeling project so I put my ficus in the garage under lights because it was too cold for it to be outside. We had a spot of cold weather so I went to check on it and found that the leaves had curled and dried and the bark appeared to have separated from the trunk and branches. Is there anything that I can do to save it? We've had "Ben" for more than 10 years. (E-mail reference)
A: Everything depends on how low the temperature got around the plant during the cold snap. The best advice I can give you is to monitor for any new growth. This will require patience on your part and treating it as if it were alive; locating it in a warm, well-lit location, watering when the soil dries but not over-watering. Do not fertilize it until or unless new growth is noted, then only at half strength. These are pretty tough plants. My wife "rescued" one years ago that had been put on the curb to be picked up by the trash hauler. I had a fit because it looked so scrawny with no more than a dozen leaves on it. But she pruned it and nurtured it back to health in spite of my misgivings.
Q: Being new in North Dakota, I have learned so much from your column. I really enjoy your helpful hints. I have an avocado plant nearly three feet tall that is growing like a cross. Can I cut the ends off to encourage it to fill out? Any other hints for keeping it alive? It looks very healthy and is about 6 months old. What about fertilizer and repotting it? (Dazey, N.D.)
A: Thank you for the nice words about the column! Concerning your avocado, this is considered a fun, temporary plant to grow. As a houseplant, they usually don't live beyond two or three years. You can pinch out the growing tip to encourage bushy growth. Repot in a minimally larger pot and use a multi-purpose potting mix such as Schultz's.
Q: I recently purchased three plants. Your column answered my questions on two plants, chenille and goldfish, but my other plant is called a dancing dolphin. I can not find any information on this plant. (E-mail reference)
A: I need a botanical name. I've looked through my seven books on houseplants and the only reference I found listed was dancing orchid. I've spread the word to some of my colleagues. If they can help, I'll gladly pass on the information.
Q: My dracaena marginata has grown to two canes near five feet tall and had been doing fine. One side lost all of its leaves, rebudded and began to grow, but then died. The other side was fine, but one day I came home to find it hanging down as if somebody had broken it. There was softness in the cane but it wasn't broken as you would break a stick. The leaves were fine, so I strapped it up with a chopstick (makes a great splint) and hoped for the best. More areas have gotten soft and the leaves are almost dead. Can I cut them off below where it is soft and hope it buds? (E-mail reference)
A: I would suggest cutting the canes back several inches below the soft areas. This will force new buds to eventually break further down the cane and develop into a nice healthy plant. Somehow your dracaena has picked up a fungal canker disease that is girdling the stem. What I have done in the past with success is to cut the plant back to about a 6-inch stub, then taken the cane and cut it up into about 4-5-inch pieces and laid them horizontally in dampened sphagnum moss for about 5-6 weeks. In that time some new buds and growth developed on one end, while roots developed on the other. In the meantime, the mother plant began breaking new growth as well!
Q: I purchased a beautiful and healthy looking China doll plant from a grocery store about six months ago. I haven’t been able to make it happy. I have it in our bedroom near a northeast facing window, and water it about once a week. It’s in a pot that drains well. The stems near the dirt are brownish. The leaves droop and then fall off. It did look healthier in the summer which makes me think it needs more light and may be getting a draft from the window. (Minot AFB)
A: The China doll is sensitive to drafts, but not central heating systems. In other words, it can tolerate the dry air of winter homes. However, it tends to drop leaves in a home environment probably due to low light plus exposure to an occasional cold blast of wind. Keep in mind that this is a native to Taiwan, so what we might not consider a problem can become one to this tropical beauty. I suggest keeping the soil uniformly moist, and locating it in a bright west or south facing window. Get supplemental lights for it if the cold air coming off the window is too much.
Q: I have a plant here that, according to my book, is a Chinese evergreen. It was green to start with, but it turned a yellow color and won't open up. I'm beginning to think it's too wet, but was rather puzzled why it turned that color. (Carrington, N.D.)
A: Being too wet or having it in a non-draining pot could be the cause of the problem. Allow it to dry somewhat between waterings and if it is not in a freely-draining container, repot at your earliest convenience.
Q: Could you please tell me how to care for a plant called "Moses-in-the-rushes"? I'm quite sure it doesn't take a lot of water, but otherwise I don't know anything else about the plant. (Rush City, Minn.)
A: I believe you mean Moses-in-the-cradle. Here are the care tips:
- Keep it warm - no lower than 55 F.
- No direct summer sun, but bright light otherwise.
- Mist foliage with distilled water frequently.
- Repot every spring.
Q: Ten years ago, our son adopted a small two-leaf plant that was left in his new apartment. He has repotted it twice and it has now grown into a 4-foot by 4-foot plant with many 6- to 8-inch leaves on it. He keeps it by a picture window near a heat register and waters it daily. He found a marker with the plant that says it is a Brossaia Actinophylia. He would like to know if he is caring for it properly and, since the main stem is dividing, would it harm the plant to separate and transplant it? (Clear Lake, S.D.)
A: The fact that he waters it every day is an indication that it needs repotting, but not necessarily in a larger pot. Obviously he is doing something right to have had the plant so long and have it be doing so well. I advise against any attempts to divide it.
Q: I have a prayer plant, bought one year ago in a little 2-inch pot. I put it in my restaurant on top of my water cooler. It grew and grew and grew. Then it began to bloom these little whitish flowers. I was told this was a sign of healthiness. It grew so large that it hung down about 2 feet all around the water cooler. Then all of a sudden it stopped flowering. I first thought that winter maybe that had something to do with it. Then I noticed that some of the leaves turned yellow. One Sunday I took the plant down and saw that where the plant crossed the edge of the pot and hung down, it looked like it was breaking. At that spot where it hung at the edge of the pot the plant stem looked like it was fraying like a rope does when it's going to break. I took the whole pot and broke it all apart. I got about 10 good pieces from it. All the little slips rooted and I've repotted the little ones in one pot. Now I'm afraid that it will do that again. What should I do? Everyone used to comment on that plant in particular. Should I get something to tie it up so it grows upward? Should I just let it grow down so it hangs but this time cut it back so it doesn't get to heavy and start breaking? (E-mail reference)
A: Just allow the plant to grow naturally, then as it begins to cascade over the edge of the pot, buffer it with a cloth or rubber edging of some kind to keep it from fraying the stems, cutting off those that get to be the longest and start the fraying process. Congratulations on having a great green thumb!
Q: I have a peace plant that I have had for about five years. The problem I am having is that it was blooming when I purchased it, and hasn't bloomed since. I have fertilized it and repotted it over the years, but still nothing. It has gotten rather large and I would love to see it bloom. Any suggestions? (E-mail reference)
A: Give it more light, but not direct sunlight. Placing it near or next to an east window will often bring it into bloom in a month or two. Congratulations on having the plant for five years! Most people cannot keep a houseplant around that long.
Q: I have a fiddle leaf fig near a sunny window. The plant leaves have now turned to grow towards the light. Is it okay to rotate the pot from time to time or is this too much for the plant? (E-mail reference)
A: Not a problem at all. It just might be easier for you to get a direct overhead light source so you wouldn't have to do that so often.
Q: I have a hoya displaying contradictory symptoms. Most of its vines are drying out at the ends while at the same time thick yellow leaves are dropping (mostly at the base of the plant). I got the plant from a lady who didn't want it. It was vined around a planter she wanted to keep so we had to cut it free. It had been in this planter for five years. I kept all the cuttings and have plants from every one of them. The mother plant had a dozen or so flower stems. All of those vines have died off. Last year I replanted it. There has been no change. The top of the soil gets dry while the bottom stays damp. I watch it closely so I don't overwater. (E-mail reference)
A: The hoya or wax plant needs warm, direct sunny locations in well-drained soil to do well. It sounds like one of those factors is missing, or a root rot has begun on the plant. I suggest you knock it out of the container, check the roots, and possibly repot or discard.
Q: I have a yucca plant which was doing very well and had lots of babies, which I cut off, repotted sold and gave away. The problem is that last summer I did the same thing and it seemed OK until about a month later. Four months later it seemed that its stalk below the soil rotted and dried up. Now the plant looks healthy but is just sitting above the pot on soil. Any advice on what I can do with this? (Fargo, N.D.)
A: The yucca plant you are referring to is really a Kalanchoe spp. that sprouts youngsters along the leaf edges that can root into new plants. It is a succulent like the yucca. I would suggest that you contact one of the folks you gave some away to earlier and see if they can return the favor so you can start anew.
Q: I had a fuchsia hanging basket over the summer, which has now died out. Before it died, I took some clippings and put them in water. They are now getting spots on them and turning yellow, one leaf at a time. I have now put them into dirt, hoping that will help. Were they getting too much water or what? (E-mail reference)
A: Cuttings of fuchsia will root readily in a perlite or vermiculite media. The pure water was too much. If you can take fresh cuttings, do so, as this is the ideal time for propagation via cuttings. Otherwise, get some seed and sow over a sterilized media without covering, as the seeds need light to germinate.
Q: We just received a beautiful potted miniature rose bush and are concerned about how to care for it since no instructions came with the plant. Can you help? We live in an apartment in Vancouver, BC, Canada. Our only window faces north. The apartment is kept at a constant 70F. (E-mail reference, Vancouver, B.C., Canada)
A: The miniature rose needs as much light as you can give it. Invest in a plant light and beam it on the plant for up to 12 hours a day. The light coming in a north window will not be enough to sustain it. Then follow up with the usual: remove flowers as they fade; cut the stem back to a leaf axil; water as needed once or twice a week with tepid water; fertilize when new growth is apparent and summer it outdoors when that season finally arrives-- although your winters in Vancouver are nothing compared to what we go through in North Dakota! You might be able to move it outdoors quite soon. Check with a local florist or nurseryman.
Q: My daughters have given me sensitive plants on Mother’s Day for a couple of years. One grew very well into a 3-foot high bush. It bloomed and seemed to be doing very well. Then, all the leaves got brown on the end and started falling off and the plant eventually died. I've tried several times since to grow another one but they all seem to have the same problem. I'm still getting new branches and leaves, but soon after they come out, they dry and drop. The plant grows upward but with few leaves. I've tried different watering techniques and different locations in the house without much luck. Any ideas? (McLeod, N.D.)
A: The sensitive plant, or Mimosa pudica, is more of a horticultural houseplant novelty than something to seriously consider as a permanent resident in the home. It requires as much natural sunlight or artificial lighting as you can provide for it. Because of the spindly growth, it should be pinched continuously to encourage bushy, compact growth, and possibly flowers. In the tropics this is a widespread weed that I have seen infest lawns like quackgrass or crabgrass does in our region. With this plant, mowing it off just encourages it to spread. Bermudagrass can't even keep it out! I don’t know what the problem with your plant is, but I would guess it has something to do with light being insufficient. It could also have something to do with the fact that it is a tropical plant growing in a house with very low humidity due to the heating system. I have never known anyone (myself included!) who has been able to keep one of these around as a houseplant for more than a few months.
Q: Can you tell me what would cause white mold to start growing on top of the soil of my houseplants? Some of the plants' leaves are turning brown and falling. Any help will be appreciated. (E-mail reference)
A: If you are sure it is white mold, then it is due to overwatering and poor drainage, which is being further reflected in your leaf discoloration and defoliation. It could also be salt accumulation from the high salts in the irrigation water, which could be exacerbated in a poorly drained pot or soil mix. In either case, I suggest repotting and using containers that are free-draining. If your water is high in salts, dilute occasionally with distilled water.
Q: Can the lead paint on a pot kill the plant inside it? (E-mail reference)
A: No! Lead was used as pottery in ancient Roman and Greek cultures, and according to history, the plants did all right. At least Pliny, the Roman naturalist and writer, never wrote about the lead killing plants. However, if you have children in the residence it would be a good idea to dump the pot.
Q: I have a question for you on my China Doll houseplant. I got this plant when it was about 6 inches tall, two years ago. It has grown to be probably about 6 feet tall. Within the last four to six months I've noticed it seems to be dropping so many of its leaves. I've checked them many times thinking it was spider mites, but it is not. I have not changed anything as far as caring for it, but the leaves turn yellow and fall off for no apparent reason. Any ideas as to why or suggestions as to what I can do to correct this problem? (Bismarck N.D.)
A: Something must have changed, whether or not you have changed your care technique for it. The plant could be root-bound, salts could be accumulating, forced air heat could be hitting the foliage, a draft from a door or nearby window could be causing defoliation. You obviously had to repot it in the past two years to have it go from a 6-inch to a 6-foot plant. Something has changed in the plant's environment. Weaker light? If you use fluorescent bulbs, their intensity decreases with age, mostly undetectable to the human eye but readily perceived by the plant, with the usual response being leaf drop to compensate for the lower light intensity.
Q: In July my daughter brought me a gardenia plant from Houston. Since bringing it into the house in October, it has had aphids. I have been using an insecticide but am still finding some insects on the plant. While there is some new growth on the plant, it doesn’t seem to be progressing and the plant is losing some leaves. I have been watering the plant three times a week using Miracid and I do spray the leaves daily. What more can I do to save my plant? (McLaughlin, S.D.)
A: You picked a tough plant to perpetuate! Gardenias and their care are for florists with expertise in that area. I suggest spraying with insecticidal soap to kill off the aphids, mites and whiteflies. Keep fertilizing with the acidifying material and keep your fingers crossed that your plant makes it into spring planting. Also, mist spray the leaves with distilled water two or three times a week.
Q: I have a large rubber plant (about 3 feet tall) and am concerned about its future. My mother had the plant in her care for four years while I was in college and it did quite well with nice full branches. Now the plant continues to grow upward but loses all of its leaves downward. It also continues to grow plenty of offshoots that do quite well. The plant has never been repotted and I noticed the soil is getting a little low in the pot. I don't water often (every couple of weeks), after an overwatering mishap about six months ago. Could this still be the result of overwatering? Or lack of sunlight, as it gets little of that? (Moorhead, Minn.)
A: The plant is reacting to a stressful event, either something recent or the watering mishap you mentioned. I advise repotting it and cutting the "pole" stem back to encourage a flush of new growth. Once the rubber plant drops its leaves, it has been my experience that they never come back again. It would be a very good idea to repot it, then practice consistent watering--not overwatering--but allow the top to dry before watering completely again, to the point that it leaches into the saucer the container is sitting in. These plants are also sensitive to drafts, either hot or cold, so be sure to place them far enough away from a window that they are not affected by any cold air coming off of it. Once in a location where they are doing all right, it is a good idea to let them remain there, as moving them elsewhere often causes defoliation.
Q: My mother-in -law has some plants (china doll, jade, Christmas cactus) in an entryway at the top of the stairs to the basement. She said they do just fine all summer and fall until they turn on a propane heater in the basement. Then the leaves of the china doll fall off and the Christmas cactus stop blooming or lose blossoms. (E-mail reference)
A: The plants are acting as the miner's canary. Your propane heater is giving off toxic fumes in low concentrations that the plants are responding to. Your mother-in-law is taking a chance with her health. I suggest venting or modification of the system in some way before regrets become reality.
Q: I bought a Norfolk pine last year and it was beautiful and full. It was growing nicely, so I transplanted it into a larger container last month. Now it is getting dry brittle branches and is dying. Is there any way to save it? (Jamestown, N.D.)
A: Start immediately to mist the pine with distilled water on a daily basis. As the outdoor temperatures go down, increase it to twice daily. Be sure the plant is not near any heating vent draft. If it doesn't stabilize, then our action has come too late, and you need to start anew with another plant.
Q: Can you give me direction on growing camellia indoors as a potted houseplant? I am wondering about temperature, light, watering, feeding and how to get them to bloom. (E-mail reference)
A: Glad to help you! Here are the recommendations: bright filtered light all year, keep them in as cool a room as possible during the fall and winter, where the temperature can range from 45 to 60 degrees. Dry winter heat will keep camellias from blooming or cause bud abortion. Stand the pot in a tray of pebbles filled with water to keep the humidity high around the plant. Keep the plant well watered throughout the active growing period, then at the end of the flowering period, water only enough to keep the mixture from drying out, a period of about six weeks. Fertilize every two weeks during the active period of growth.
Q: What can you tell me about "Lemon Grass?" I was curious and purchased some. It is potted and growing very well. Will it produce lemons? (Jamestown, N.D.)
A: Lemongrass -- Cymbopogon citratus-- doesn’t produce lemons, but it produces a lemon-like scent from the essential oils that are in the leaves. Bruise or break a leaf and you will note the lemon fragrance. This plant is used in Sri Lanka and Thailand for food preparation. It is also used medicinally in Brazil and Caribbean to settle nervous stomach disorders. The Cubans use it to control ring worm and lower blood pressure. What more could we ask of a plant?
Q: I would like to know if there are any houseplants that are good for people with allergies. Which plants irritate allergies most? I am allergic to plants that put off a strong odor, such as some lilies. I really enjoy houseplants, but I need to find the right kind. (Minot, N.D.)
A: Houseplants like the rubber tree family (Ficus spp.) are good, along with dumbcane (providing you don't eat it!), English ivy, Swedish ivy, snazaske plant, and umbrella tree (Schefflera spp.). These almost never flower and can be used throughout the house in many settings.
Q: I have several questions. We have a Rose Tree of China shrub in our yard. It's gotten pretty big--6 feet across and 4 feet high. How should I prune it? Can I trim it all around? Is it wise to till around evergreens? Can you give me a guide as to how far from the ground the bottom branches of shade trees should be? Also, we have a Russian olive tree and it's leaning away from larger trees and isn't a nice looking tree anymore. If I cut it back to about 3 or 4 feet from the ground, will it come back? (Aneta, N.D.)
A: Here are several answers. Prune your Rose Tree of China shrub selectively, removing just the oldest canes right back to the ground. Prune out no more than one-third of the entire mass at one time. Carry it out early next spring before new growth occurs. No, it's not wise to till around evergreens. Keep the bottoms of your shade trees high enough from the ground so that you can walk under them. It's probably better to remove the Russian olive.
Q: Can you tell me why my tree, a house plant, is dropping its leaves? (Parshall, N.D.)
A: Leaf drop with many houseplant species is directly related to a change in environment -- a reduction in light, alteration of watering regime, temperature shifts, radical changes in humidity. If you have moved it recently, from one room to another, or to a new location in the same room, that would be enough to initiate leaf drop. After a period of four to six weeks the tree should stabilize, with a little to no further leaf drop.
Q: I purchased a Norfolk pine tree for my Christmas tree and really enjoy it. I would also like to enjoy it for a long time. Do I have to trim it? Is the north light okay or should it have sunlight? Do I mist it? Can I put it outside in the spring after frost danger? What location? Keep it in pot or ground soil? (Minot, N.D.)
A: Norfolk Island Pines enjoy being left alone once they have been properly located. Except for watering and misting of the foliage in the winter, they should never be pruned or placed in direct sunlight. Never place them in front of a forced air heating vent. Try to find a nice, cool location (north window is fine) with as much natural light as possible. Re-pot every four or five years.
Q: I have several bromeliads that were given to me after they had bloomed several years ago. One is growing really well but doesn't bloom. I've tried the technique of putting the plant inside a closed plastic bag with a cut apple. The apple spoils but that didn't help. I'd love to see it bloom after all my years of caring for it. (McClusky, N.D.)
A: With bromeliads another ingredient is necessary--patience. Try the apple-and-plant-in-a-plastic-bag again. Normally, they bloom from one to six months after the plant has been removed from the bag. Keep the apple/plant-and-bag combo in contact for no more than four to five days. Be sure the plant is getting bright, indirect light. Never give up!
Q: Would you please tell me how you put a shamrock to rest, how long it should be in a rest period, and do you cut it down? (E-mail reference, Ayr, N.D.)
A: I'm afraid that you've got me on this question. I know they need some rest, but how much, I don't know. Usually six to eight weeks is a sufficient rest period for many plants, and generally they are allowed to dry down. I will stand corrected by anyone who will come up with more concrete information than this.
Q: Enclosed is a leaf from my peace plant. The leaves are turning brown. Can you tell me why? I transplanted it this September and it was really root bound. I feed and water it once a week. What am I doing wrong? (Jamestown, N.D.)
A: I suspect that it is getting too much fertilizer or the container is not free-draining. The damage looks like salt burn.
Q: I have a houseplant that I thought was called a shamrock. It has three triangular shaped leaves and gets small white flowers. It grows from small pinecone looking bulbs. Lately, the leaves have been turning brown from the tips. I have looked for bugs but can't find anything. I did put them outside early this spring and thought the frost might have gotten them, but the new growth is still doing the same thing. Can you help me with the name of the plant and what is wrong with it? (E-mail reference)
A: Shamrock is a term given to clovers, the three-leaf and four-leaf ("lucky") types. The plant grows by runners, and I suspect that is what is turning brown. If you can peg or keep the tips in contact with the soil and keep the soil moist, they should root and not brown up on you. "Shamrocks" need regular fertilization too; once a month with a houseplant material. Shamrocks have been considered by the Irish as good-luck symbols since earliest times, with the superstition persisting today whether one is Irish or not. Officially, the shamrock has been identified by the US Department of Agriculture as Trifolium repens, or white clove.
Q: I would like to know what kind of vine the enclosed sample is from and if it would be okay to bring it into North Dakota. (Jamestown, N.D.)
A: The plant is known as Virginia creeper. It is readily available at most garden centers in North Dakota, and it thrives!
Q: I received a rubber plant as a gift and now I need to know how to take care of it. How often do I water it and when do I fertilize? Can I use plant shine on the leaves? (Grafton, N.D.)
A: Water with care. The soil must be dried out somewhat between waterings. Make sure the water is tepid, or room temperature, especially during winter months. I don’t recommend leaf shine - simply a damp cloth will do. Fertilize once a month from spring (April) through fall (October), and not at all during winter. The biggest danger to this species is over-watering.
Q: I was reading something on the World Wide Web the other day that suggested distilled water is bad for house plants (especially African violets) because it can rob the plants of essential salts. Then in some responses you wrote you seemed to be advocating distilled water. Can you give me some direction on this issue? (E-mail reference)
A: Distilled water is ionless, and continued use of it in a soilless media would indeed leach it free of just about all nutrients. However, in our part of the country water is quite often loaded with salts, resulting eventually in salt build-up to the point of toxicity, or at least some physical damage. When I was working in Saudi Arabia back in the early '80s, I saw dramatically how nearly distilled water (10 ppm soluble salts) resulted in a very positive growth response to our nursery stock after being stifled by too many salts. So my advice is, if chronic salt problems exist with your water supply, water about once per month with distilled water to leach some of those salts out of the soil mix; or, if you want to control what salts the plant gets, then use distilled water as the base, adding just small amounts of the needed nutrients each time. Keep in mind too, that all soils, with the exception of sand, have a pretty decent cation exchange capacity, which hold the nutrients against leaching water. The most leachable nutrient is nitrogen, which is easily replaced if needed, but most houseplants do not need a great deal of this element anyway to grow normally.
Q: I have been trying to find information on Chlorophytum and can't find much. I was hoping you could tell me if it is a native or domesticated plant and what country or region it originated from. (E-mail reference)
A: This is a houseplant that has been around for more than 200 years, originating from the country of South Africa, which to some is nearly a horticultural paradise. It "prefers" moist soil conditions, but don't believe it! I've had one growing in my house for over a decade now, and it gets watered about twice a month, if we think about it (which reminds me...). It is an extremely durable plant, tolerating low light conditions better than most through the winter months, and is a propagator's dream, producing all the off-shoots that make new plants.
Q: I received a catalog that features dwarf citrus trees for home and garden. They list three trees, Kaffir Lime, Meyer Improved Lemon and a Washington Navel Orange. The catalog states that the trees are easy to grow indoors, and you can move them outdoors during our summer months. Eight- to12-inch branched plants are available for $26.95 each. Do you think I would have any chance of getting one of these trees to grow indoors? Are there special requirements for citrus trees? Are they available at our local nurseries? (E-mail reference)
A: Yes, citrus can be successfully grown indoors with supplemental lights and summered outdoors. Simply treat them like any other houseplant that requires high light intensity and ample moisture, along with regular fertilization, and everything should be all right.
Q. I have a dwarf tangerine plant growing in house. It's about 2 1/2 feet tall. Should I let it grow taller or can I cut it down so it will extend to the sides? It has only one stem or trunk with no side shoots. (E-mail reference, Hague, N.D.)
A: Yes. Simply cut it back to just above where a leaf is growing. Don't cut back any more than one-third the length of the stem for now. Be sure to give it as much light as possible.
Q: Enclosed is a sample from my coleus. Can you tell me what the fuzzy white clumps are and how to treat it? (Wimbledon, N.D.)
A: The plant has a bad dose of cottony-cushion scale. I suggest making up a solution of insecticidal soap, wrapping some aluminum foil over the top of the pot, and dipping the aerial part of the plant into it and swishing it around. That should take care of them!
Q: I am in third grade and very interested in plants that eat bugs, like the Venus flytrap. Can you tell me anything about them? (Grand Forks, N.D.)
A: Venus flytraps are plants that live in the tropical forests in highly acid soil that is high in organic matter but low in mineral fertility. When they trap an insect, they are supplementing their diets so they can better survive in the low-fertility soil.
Venus flytraps attract insects with nectar. Once inside, the insect brushes against the plant's sensitive hairs that trigger the trap. The trap slowly closes more and more tightly as the struggling insect continues to brush up against the hairs. When fully closed, enzymes (like digestive juices) begin to digest or absorb body fluids from the insect. The trap stays closed for about a week during this time and opens again when the digestion process is complete.
Venus flytraps can thrive in the home or classroom environment when they are grown in a terrarium (covered glass bowl) in sphagnum peat moss. You or someone else would have to catch flies or other insects and put them in the terrarium occasionally. Water the plant with rain water or melted snow (close to pure water) to keep the soil acid. Place the plant in a bright window or under lights used to grow plants, and it should thrive for you!
Q: I recall reading in one of your columns years ago that our water quality changes during the year, and this can cause our houseplants to react in an unfavorable way. You have also said that chemically softened water will eventually kill most houseplants. Can you offer some solutions to these dilemmas? (Dickinson, N.D., e-mail)
A: Yes, there are some alternatives. Water that is very high in salts is common in many water supplies throughout our region. These salts would include sodium, calcium and magnesium. When the concentrations get high enough, these salts can cause leaf necrosis (speckling of the leaves), leaf burn (drying of leaf tips and margins) and leaf drop in severe cases.
When the concentration of calcium and magnesium is high (more than 150 parts per million) the water is termed "hard." The hardness of the water is measured by its electrical conductivity. The higher the conductivity, the harder the water. This hardness makes the water difficult for laundry or bubble bath soap to work. Households correct this with a water softener, replacing the hard ions of calcium and magnesium with sodium, which is also not good for plants (humans either).
What to do? Some options: purchase distilled water and use that consistently, or purchase a water distiller to have a constant supply. Another system, which I use with my own houseplants, is the RO (reverse osmosis) system. This allows the household to have drinking water with ample amounts remaining to be used for houseplants.
Most municipalities will also add fluoride and chlorine to the water supply for health reasons. Unfortunately, these ions will also cause some of the same injury to some houseplants. The most susceptible are spider plant, wandering jew, prayer plant, certain palms and Hawaiian Ti.
Q: I am not a gardener as I live in an apartment, but I do have a few indoor plants. About eight years ago I brought home from Florida a miniature orange tree that bears fruit about the size of a walnut. I have had good luck with the tree indoors, and it has produced as many as 100 oranges in one season. Two years ago I cut it back rather severely because it was getting too big, and this year it again had 96 oranges. It measures about 30 inches tall by about 30 inches across. I have started more than a dozen new trees from the seeds taken from an orange, but none of them would bear fruit. (Fargo, N.D.)
A: Generally, fruit trees--especially citrus trees--will not bear fruit until they are mature. This means that your trees are enjoying an extended juvenility before settling down and bearing a "family" of fruit. You can hasten this maturing process by not being so good to the trees. Hold back on the fertilizer and water a little, and keep the trees in the same pots to encourage root binding. A couple of months of this benign maltreatment should get those juveniles to produce some fruit.
Q. We replaced all the house's old leaky windows with new ones having what they called "low-E" glass. They're wonderful for keeping the winter warm and the summer cool, but I wonder if they block too much of what our houseplants need of sunlight. They seem to get pale and leggy even in the sunniest windows. (Palermo, N.D.)
A. You bet! I don't know the range of light that is being blocked, but it has to be within the range that helps produce chlorophyll. There are "spot plant lights" which you can use to overcome this.
Q. I would like to know if there are any houseplants that are good for people with allergies. Which plants irritate allergies most? I am allergic to plants that put off a strong odor, such as some lilies. I really enjoy houseplants, but I need to find the right kind. (Minot, N.D.)
A. Houseplants like the rubber tree family (Ficus spp.) are good, along with dumbcane (providing you don't eat it!), English ivy, Swedish ivy, snazaske plant, and umbrella tree (Schefflera spp.). These almost never flower and can be used throughout the house in many settings.
Q. Can you tell me what is causing mold to grow on my houseplants, and how to get rid of it? (Minot, N.D.)
A. There are two molds—a saprophyte that grows on moist soil, and a parasite that grows on living tissue. Control both by improving drainage, limiting water, and dusting with sulfur-based fungicides.
Something is out of balance—light, drainage, air circulation, moisture—to cause mold to form.
Q. I have seen a lot of answers about the hoya plant in your column. Just to let you know my hoya has nine blooms on right now, so it will be in full bloom for Easter. It hangs in a west window in the dining room with a humidifier in the room also. Keep up the good work with your column; I enjoy reading it. (Westport, S.D., e-mail)
A. Thank you for the encouraging words and the news about your beautiful hoya! I bet it is a knockout. With the days getting longer and warmer, we will see a big reduction in the need for as much indoor heating compared to the last four months. This alone will wake-up many indoor plants with renewed growth and possible flowering.
Your vigilance in houseplant care is obviously paying off. You keep up the good work!
Q. I start my plants under fluorescent lights for 16 hours a day and get very good results. May I get the same results with 12 hours a day? (Dazey, N.D.)
A. I don't know. Give it a try! It all depends on the plant requirement for light. Some need 16 hours, other don't.
It would seem unlikely to me that 12 hours of light would result in equal growth response, compared to 16 hours. However, the result may be good enough!
Q. I've been using water from our sump pump to water my houseplants, and I was told recently that after water runs through the soil it is not good for plants. Is this true? (e-mail)
A. Typically, the water that comes through the sump pump is high in salts and could stunt or kill some house plants. I don't know how long you have been able to get away with it, but if you have no visible symptoms, then don't worry about it! I would suggest leaching the salts with distilled water about every four to six weeks.
Q: Please help! I have this houseplant that I don't know the name of, but it is slowly dying. I love houseplants, but they always die four to six months after I bring them home. I water only when the soil is dry, but it doesn't seem to be helping. Please send your expertise because I would love to have a green thumb. (Rockham, S.D.)
A. Your plant appears to be a shamrock, and it looks as if it is suffering from salt burn or rotting roots. Try repotting in a high organic soil and free-draining pot. May your thumb turn green!
Q. Can you tell me what I am doing wrong with my plant? A new shoot comes up and one or maybe two start curling up and die. I have enclosed a sample for you to look at. (Jamestown, N.D.)
A. I cannot tell what is causing your plant (Maranta spp) to die from the sample you sent. Refer to "Interior Plantscaping with Large Houseplants" (H-1123), an NDSU Extension Service publication. The last page of this lists the top 10 most common diagnostic problems with interior plants.
Q: I have had an iceplant (that's what I call it anyway) for 30 years, and its leaves have always been small. Recently, I went to a friend's house who has the same plant, and hers had large leaves. I asked here what she was doing to it, and she said she watered it with coffee. Now I water mine with coffee--not all the time--but the leaves are getting bigger too. Why? (Orient, S.D., e-mail)
A: Coffee "wakes" a plant up to many new avenues of life! Coffee, as you know, is a complex liquid, which also has an acid pH. Although there's no controlled research to prove it, I suspect that the acidifying effect the coffee is having on your soil's pH helps to release some of the nutrients that would otherwise be unavailable. There are likely many other growth-stimulating compounds in coffee as well, but I think the acid pH is the biggest help in our high pH soils and water.
Q: I would like to learn how to grow ferns from date pits. Any other information on growing plants from food products and seeds, I would like too. (Peterson, Iowa)
A: Refer to the following extension publications: "How to Succeed at Seed Starting" (H-1139) and "Home Propagation Techniques" (NCR-274).
Q: My neighbor across the street moved away and gave me a gorgeous 7-foot-tall Queensland umbrella. He kept it away from the window, as the sun shines directly in on his side of the street. I have solar screens on my windows, but the sun tends to come through diffused anyway. Since I’ve had the plant, the bottom row of leaves are turning speckled, with yellow and green spots. My former neighbor fed the plant every three weeks with a name-brand plant food and misted its leaves every week. Do you think this plant will acclimatize on its own? How often should I water it? Should I install grow lights (I have some fluorescent lights on hand), and if so, how many hours per day should a plant like this be exposed to fluorescent grow lights? I'm normally good with small plants, but this big beauty has me stumped ... and worried. (Kennewick, Wash., e-mail)
A: First of all, congratulations on being on such good terms with your neighbor that you would be given such a fine specimen. The umbrella tree will require bright-but-indirect light to maintain its present foliage cover. It is, however, one of the most adaptable plants for acclimatizing to lower light levels. It does this by dropping some of the older leaves first, until it is at equilibrium with the energy input. The plant will be better looking and you likely happier if it is given strong indirect light--fluorescent being acceptable. Give it eight to 10 hours at first to see how the plant responds. If it continues to lose foliage, up the duration to 12 hours or more. Keep in mind that the farther the plant is from the light source, the less the intensity of the light reaching the plant. There are three important light factors that affect the survival of plants: intensity, duration and quality. If you can borrow a light meter from a local florist or greenhouse, try to position your lights so that between 150 to 200 foot candles (fc) are at the surface of the top part of the plant. Watering is not a problem. If you are not getting any new growth being generated due to low exterior light coming into the window for the season, then keep your plant on the dry side. As the plant begins new growth with lengthening days (either from you or Mother Nature), then keep the soil moist to the touch. And here’s one final important point: Keep the foliage wiped clean with a water-soaked sponge at least once a month (top and bottom) to keep dust from accumulating and to prevent spider mites from taking up residency.
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