January 23, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: I have several books that have pages on strawberries but none tell me what to do with last year’s growth. The strawberries were planted last year and the foliage is still attached. Should I pull it off, rake it, mow it off or leave it on to protect the crowns? When is the best time to remove the old foliage? Should you use the berries from the plant the first year? Should I fertilize the plants? Should you mulch strawberry plants over the winter or can they survive without being mulched? (Armour, S.D.)

A: You’ve asked enough questions on strawberries to develop a course on the subject! Obviously at this time of year - midwinter - you do nothing to the foliage of the berries. Typically I mow the foliage back in the fall before freeze-up or snow cover sets in. The first year flowers should be removed to keep berries from being set. That allows more energy to go into root and aerial plant development. On small patches this is not a problem, although I know many people do not follow this suggestion as they are too anxious to get the fresh fruit. Fertilization is recommended with a garden type fertilizer, such as 5-10-10 or something similar, just as new growth is beginning. Mulching is a personal choice. I have never mulched them in Fargo, nor years ago when I had a small farm in upstate N.Y. Many people will mulch them with clean straw or with a geotextile fiber known as Remay. If you are growing berries for the money, then I would suggest mulching. If you’re growing strawberries for your own consumption and yield isn't important, then you may choose not to, as long as your area gets dependable snow cover.

Q: My problem is with my amaryllis. It grew, bloomed, and now I have long leaves. My problem is the time of year in relation to its internal calendar. It's January and I haven't seen a bloom since last February. I recently stopped watering it but now the leaves are limp. It is usually in a south-facing window. I'm not sure if I should be bringing it to dormancy in cool, dark place or keep watering it until it decides to die back. (E-mail reference)

A: I couldn't determine from your e-mail whether or not you had allowed it to die down in the fall for about 6-8 weeks (dormancy) and began watering it after that period. Keep in mind that amaryllis is a tropical plant. It goes from a rainy to dry season (dormancy). It reblooms when the rains return. If you allow it to dry down as I have suggested, you may get it to bloom. If not, dump it and begin anew. It isn't worth the frustration.

Q: I am seeking info on how to save my medium-sized ficus tree as well as get rid of the small gnats that seem to be coming from its soil. It is in a window facing west and receives filtered sun. I try to let the soil dry out prior to watering each time and keep the topsoil free of debris and dead leaves. There are no spots or scales on the backs of the leaves but it has been dropping leaves steadily now for about a month. Is there a spray for the bugs that will not harm the tree? (E-mail reference)

A: The plant should probably be repotted with fresh soil that is free of insect activity. When you repot, look carefully at the roots to see if there is any evidence of root feeding from the larval stage of the gnats or any other insect that might be harbored in the old soil. Generally, potent insecticides are not recommended for indoor plant use. The ones that are suggested, such as insecticidal soap, are good knock-down types that are mostly ineffective unless direct contact is made with the insect. Check to be sure the plant is not in any drafts from the heating unit, or near a door that gives it a cold blast of air each time it is opened and closed.

Q: Anniversary time. What is the best way to keep cut flowers longer that are in a vase of water? (E-mail reference)

A: Happy anniversary! The type of flower you select is important. Carnations last a lot longer than do roses but the message can be just as passionate! Getting a combination of pink carnations and white daisies bespeaks of your love. Pink carnations mean "I will never forget you," and white daisy means "loyal love" which you obviously have. You can throw in a red rose or two which means "passionate love" if you want to cover all the bases! If that doesn't answer your question, try anything that acidifies the water such as vinegar, unbuffered aspirin, etc. Also, changing the water on a regular basis is a big help! Making fresh cuts on the stems will keep the water flowing to the tops. The florist you purchase them from may have some more up-to-date materials that might be more effective. Expect the roses to fade first, but don't worry, that is no indication of a loss of passion. If you buy them with a tight bud they will last longer than if they are partially open.

Q: I have a ficus tree that I got in June at my father's funeral. All of the leaves fell off. Now there is new growth at the bottom of the dead part. I don’t know anything about plants but I really want to keep this tree alive. When you say cut the dead part away, how much do you mean? The entire top is dead. How often should I water it? How do I know when it’s time to water it? (E-mail reference)

A: If there is no green cambium tissue under the bark when you scrape it with your fingernail, the plant is truly dead, and there is nothing you can do at this point to revive it. If there is still some green tissue, then cut it back to about a 6-inch stub and water it normally in a bright location. It should send out some leaves in about six weeks if it is going to at all, otherwise, it is a goner.

Q: My Christmas cactus was doing well this season. It had lots of flowers for the holidays but then my cat decided to do some pruning and broke off several stalks at the soil line. I just laid the leaves on the rocks that are on top of the soil. Yesterday I noticed they are sprouting little roots. Now what do I do?

A: Plant them!

Q: I picked up some rhizomes at a discount department store late this fall only to have it snow before I got them in the ground. How do I store them over the winter so they have the best chance of making it in the spring? How about daylilies? I thought the price was right. Maybe the bargain was too good to be true. (E-mail reference)

A: Store them in a cool, dry, dark location until you can get them into the ground. The same for daylilies. You probably will not get 100 percent survival but at least some will make it through. Discard any that are mushy or showing other signs of deterioration.

Q: I have a Norfolk Island pine tree that is four feet tall. Please tell me how to repot it in a much bigger pot so hopefully it will grow to seven or eight feet tall indoors. (E-mail reference)

A: Get the next size container for repotting. Then get some good potting soil that is high in organic matter that is labeled either "sterilized" or "pasteurized." Spread out newspaper and carefully knock the plant out of the pot by having one person hold the pot upside down and knocking on the bottom with the heal of their hand, while you hold your hands over the top of the plant to catch the soil ball as it comes out. This will work better if the soil is slightly moist. Estimate how much of the potting soil will have to be added to the new container, place it within, and carefully set the rootball in the new container so that the top of the ball has about a 1-inch lip of pot around the edge. Carefully place the potting soil around the edge of the rootball and the container, water in, and add more if the soil settles. When finished, set the plant back in the same location it was prior to planting.

Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Rich Mattern, (701) 231-6136, richard.mattern@ndsu.nodak.edu