Ron Smith, Extension Horticulturist, NDSU Extension
A: It is rare for indoor azaleas make it beyond the initial blooming stage that the growers have induced. I suggest that you dump it, but, if you donít wish to do that, to plant it outdoors for the summer in a 50/50 mix of peat moss and sand to see if it recovers. If it does, great--count yourself among the rarely successful!
A: Average temperatures, bright light--even direct sunlight on occasion--water liberally except in winter, mist leaves when plant is not in bloom (use distilled water). If repotting is necessary, do so in the spring.
A: Your question is kind of like asking a doctor if you should take vitamins; the answer is, only if you need them. In other words, if your plant is deficient in magnesium or sulfur, the elements that make up Epsom salts, then you will see a positive response to the application. If it isn't, then there will be very little to no response. In this particular case, there is no harm in trying and see what the result is. Just don't overdo it, as we Americans typically do so many things!
Q: I just replanted my two philodendron plants into larger pots and now they both appear to not be doing so well. A few of their leaves have turned bright yellow and appear to be dying. I water them with distilled water only and they get a moderate amount of sunlight. They were flourishing before I repotted them. What did I do wrong and what can I do to prevent them from dying? (E-mail reference)
A: Generally, the philodendron group is a pretty durable one to select from for houseplants, so I doubt your problem is a serious one. Check your watering habits. The Monstera philodendron likes to have the soil just moist during the winter months. Keeping it too wet (which is common right after repotting) causes waterlogging and could lead to the leaves turning yellow. Another cause for foliar yellowing is underfeeding. While not heavy feeders, they do need a fertilization at least every 60 days in the normal potting soil. When you say they get a moderate amount of sunlight, I assume you have them placed in the same location that you previously had them in. They should never receive direct sunlight, only bright, diffused light.
Q: My praying hands plant has brown spots on the edge of its leaves. What could it be from? I don't water my plants unless they feel dry when I feel the top of the soil. The Christmas cactus is doing really good and blossoming along with the rest of my plants. (Carrington, N.D.)
A: The prayer plant (Maranta spp.) is sensitive to being underwatered. While such treatment is good for Christmas cacti, it causes problems with this species. Unlike many (if not most) houseplants, the soil should be kept moist at all times--do not allow it to dry out.
Other possible causes of brown leaf spots could be dry air or too much direct light. Mist the foliage often with distilled water, and keep in mind that the sunlight intensity and duration is on the increase now, so exposure that wouldn't cause harm two or three months ago could be the culprit now. Be sure to remove any badly affected leaves.
Q: I own a gold mosaic houseplant and have it in my greenhouse. It was purchased the first week of February. When I brought it home the temperature was about 30 F. The leaves are curled up on the edges and some brown spots appeared. I stopped watering it as it is still moist. Are these symptoms due to a cold draft, the wrong temperature when the plant was purchased or too much water? (e-mail)
A: I'm sorry, but I don't know what a "gold mosaic" houseplant is. Do you have the botanical name? If you can give that to me or a more detailed description of what it looks like, I could give you the cultural requirements.
From the symptoms you describe, it sounds like the plant was troubled by the exposure to the cold draft when bringing it home, and then compounded by keeping it too moist. You are smart to back off on the watering. Allow it to dry between watering cycles. I often tell people who are troubled by their overwatering habits to wait 24 hours to water when the urge hits to water the plant!
Q: We have a dragon's tongue plant that keeps tipping over since we repotted it. Should we add more dirt or simply stake it up? (Fargo, N.D., e-mail)
A. I suppose you mean the Madagascar dragon tree (Dracaena marginata). I would simply stake it until the roots take hold in their new setting in about six to eight weeks.
Q: The tips of the leaves on one of my houseplants always turn brown, and I am not sure why. (Stanley, N.D.)
A: A number of factors could be causing the brown tips. One often is the fluoride, either in the water or potting soil which can contain amendments such as perlite or vermiculite. It could also be the result of a salt buildup, a cold draft or too much sunlight at once. My best guess is that it is either a fluoride burn or minor soil toxicity.
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. We collect rainwater from the roof and use it for houseplants as well as the garden. Could the blight bacteria be in the rainwater? My kitchen herbs are blackening, and the impatiens outdoors are also showing brown leaves.
A. Has your roof been re-shingled in recent years? Could be some chemical toxins coming off that. The fireblight bacterium doesn't infect all plant material, of course. You could also be getting Pythicum fungus started on your plants.
Q: Can you tell me why my garden and houseplants are turning brown? (Mobridge, S.D.)
A. There can be many reasons for houseplants to have problems. Here is a listing of the more common ones:
- Being kept too wet.
- High salts in the water.
- Too low a light intensity.
- Poor, or no free drainage from the container.
- Plants in a draft location.
Q: I have this plant that has long runners, but some of the leaves are turning yellow with black spots. Why? (Enderlin, N.D.)
A: Your plant is known as Maranta leuconeura massangeana or Prayer plant. The likely cause of leaf discoloration could be a nutrient deficiency, not enough light, roots in poor condition, and under watering. The black spots are most likely a fungal disease. I suggest repotting in a freely-draining container with a high humus potting soil. An African violet-type soil would be a good choice. Pick off all affected leaves, water with high quality (low salt) water, keeping the soil continuously moist but not water-logged. Fertilize once a month in summer, once every two months in winter.
Q: I have a question about my Croton houseplant. May I cut it off since it lost all the bottom leaves? Can I replant the top bushy plant where the leaves are good? I do have a new seedling that is doing great at the bottom. Does this Croton plant ever need fertilizer? (Gackle, N.D.)
A: Crotons can be cut back when they become too large or ungainly looking. The stem that has been cut back will eventually make new growth. When you cut the Croton (more properly known as Codiaeums) it will bleed a milky latex typical of members of the Euphorbiaceae family. Spray the cut ends with water or dust them with powdered charcoal to stop the flow of latex. With the cutting, reduce it to about 6 inches long for faster rooting and easier handling. Plant the cutting in a 3-inch pot of moist, equal parts mix of peat moss and coarse sand or perlite and enclose everything in a clear plastic bag and place the plant where it can get plenty of bright, but indirect light every day. When new growth is evident, that means the cutting has rooted and the bag can be removed. Next spring it will likely need repotting as the roots will have filled the 3-inch pot space completely.
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