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Ron Smith answers questions about plants, trees and gardens.

By Ron Smith, Horticulturist

NDSU Extension Service

Readers: In a column a few weeks ago, there was a question about grafting a sheep nose apple tree. We have had two offers to help with the grafting. One is from Jim Walla, North Dakota State University research scientist in the Plant Sciences Department. Walla can be contacted at (701) 231-7069 or at The other offer of help came from Alan Leighton at the Plantsmyth Nursery in Rapid City, S.D. Leighton can be contacted at (605) 348-3387 or by e-mail at

Q: I purchased tulip bulbs and put them in the refrigerator. The bulbs have small shoots on them, but do not appear to be growing. The bulbs also are large and healthy looking. I would like to plant them so they will bloom this spring. Is there a particular method I can use to make this happen? (Ozark, Mo.)

A: Any way you can get them into the ground or any soil will suit them just fine! Large bulbs should put on a good show for you. Enjoy!

Q: Our neighbor has a mature apple tree in her yard that was pruned by some volunteers with chainsaws. The tree was overgrown, but it flowered beautifully in the spring. The tree is a showstopper in our neighborhood. It was pruned back extensively, maybe as much as 75 percent. Now the bark is peeling from the trunk and branches. Is there anything that can be done to save the tree? (e-mail reference)

A: Keeping your fingers crossed is about as good as anything I can recommend. I can just imagine what the poor tree must look like! While this treatment doesn't kill the tree immediately, it eventually leads to its demise. The tree will look ugly as it is going downhill. Backyard apple trees should not be pruned with chainsaws because mistakes can be made too quickly, especially by amateurs. Someone who knows what he or she is doing should prune any tree of value. The best bet for doing the work is an International Society of Arboriculture certified arborist. I'm sure it was not the intention of the volunteers to kill the tree. However, just because someone knows how to use a chainsaw without cutting his or her fingers off doesn't make him or her a good tree pruner.

Q: A small bougainvillea came with the place we purchased. During the spring and summer, it grew very tall and bloomed often. It's winter now in California, so the plant has lost most of its leaves and looks scraggly. Am I supposed to cut it back? I have no idea how to care for this plant or any of the other plants that came with the house. (e-mail reference)

A: I could assist you, but I know you would be better off contacting someone locally. Go to the University of California Agriculture and Natural Resources Web site at Click on the county you live in to get phone numbers or e-mail addresses of horticulturists who are in a good position to assist you with this and other questions you undoubtedly will have.

Q: My husband purchased a weeping pussy willow tree for my birthday last spring. The plant was in good health. I planted it in my front flower garden and it seemed to be doing well for the first few weeks, but then the limbs on top turned brown and the white buds dried up. The trunk of the tree remained healthy and new limbs grew along the trunk. I trimmed most of the new limbs off because they were growing on the lower part of the trunk. I tried to train some of the new upper limbs to weep, but without success. Do you think the top of the tree will come back in the spring? Is this common and do you have any suggestions on bringing this tree back to life? (e-mail reference)

A: From your description, it sounds like the top part of the tree died for some reason. My best guess is that insects caused it. It could be borers or bark beetles that girdled the top part of the tree. Take a close look at the dead part. Go down to the base of the branch to see if there are any holes. If so, that is what caused this part of the tree to die. If not, then it could be a fungal canker that developed in the cambium and girdled the tree, which killed the upper part. From your description, there likely is no life left in the upper part of the tree. You can work with the remainder of the plant to make it look like more of a shrub or get a replacement, which is what I would suggest.

Q: I got a spider plant a few months ago. I had the plant in a little glass of water until the roots came out. After that, I planted it in a clay pot with a hole in the bottom. For the past couple of weeks, I have noticed that the sides of the leaves are turning a nasty brown, but only on the sides. The brown parts are not drying up and falling off like some of the tips do. I am not sure what I am doing to make this happen. The plant is in on a windowsill on the back of the house, so it only gets sunlight for a short time in the morning. We use good-quality well water. (e-mail reference)

A: This is a symptom of salt burning that I suspect may be in the soil you used. If it was commercially available potting soil that you purchased at a retail outlet, this shouldn't be happening unless you have used fertilizer in excess. I would suggest repotting it in fresh soil to see if that corrects the problem. I assume that the water supply from the well is not high in soluble salts. Have you had the water tested for that? Generally, these are among the easiest plants to grow, so doing something simple, such as repotting, may solve the problem.

Q: I have several petunias that are doing extremely well. However, one plant is producing green, leathery flowers instead of the softer blooms I expected. I do not use weed sprays and apply only liquid seaweed or manure pellets. I gather it’s a hormonal problem, but I do not understand how or why this is happening. There does not appear to be any seedpods on the spent blooms. The soil is sandy and has a good layer of light mulching on top. I water the plants twice a week and they get full sun exposure. (e-mail reference)

A: It sounds like the petunia could be suffering from a phytoplasma known as aster yellows. Unfortunately, there is no cure for the problem. About the only thing you can do is remove the affected plant before the problem spreads. Controlling the leafhoppers and weeds in the area would go a long way in arresting the further spread of this disease.

Q: What is the home propagation technique for geraniums? I have a plant that I don't know where to cut. (e-mail reference)

A: Cut a stem that does not have a flower on it to a length of 4 to 6 inches. Place the cutting in a sterile/pasteurized media of sand/peat, perlite or vermiculite. Keep the media moist and the cutting in full sun or under a plant light. The cutting should grow roots in four to six weeks or even less.

Q: I just found your Web site. I have a question about our evergreen trees. Our corner tree had small, white specks on the needles. These specks now have moved to four other trees. I found a tiny black speck inside that is about the size of a pinhead. Is this scale? If so, what can I do about the problem? We live at 7,000 feet and water our trees once a month during the spring and summer. Our trees are beautiful, so we would hate to lose even one. I contacted our local Extension Service office, but have not received an answer. (e-mail reference)

A: If you live at 7,000 feet, then I know you are not in North Dakota. What you describe does sound like a scale insect problem, which is something you want to get under control quickly. There are several products on the market, such as Merit and Ortho, that use the same active ingredient. These products, when applied properly, will give you up to 12 months of control through systemic action. That means that only the plant-feeding insects will be affected. Give the local Extension Service folks another call. Your message may have fallen through the cracks somewhere because I know they would be glad to assist you.

Q: I have a young ficus Benjamina that I repotted about six months ago. It hasn't lost many of its leaves, but it isn't growing. It has plenty of room in the new pot to do so. Should I use root hormones? If so, what should I use? (e-mail reference)

A: Do not use root hormones. Instead, have patience! You didn't say where you have the plant located as far as light goes. My guess is that it is in a relatively low-light situation. You might try giving the plant supplemental light from a plant light for 12 hours a day to stimulate growth or wait until spring to get natural sunlight reaching it indirectly. Don't try to force it with fertilizers or growth hormones because they won't work.

Q: Recent cold temperatures caused major damage to my gardenia and hibiscus shrubs. Will they survive? Should I trim off the damaged limbs? Should I water the plants more or less than usual? It’s our dry season, so the usual watering to me is 2 to 3 gallons per week. The gardenias are mature, but the hibiscus trees were just planted. Should I feed or do anything else? (Punta Gorda, Fla.)

A: The plants were nipped by the low temperatures, but should recover. Do not adjust anything in your care regime. Keep everything the same, except for the pruning back of the damaged branches.

Q: We bought a house last summer that has a lilac bush near it. The bush is overgrown and as tall as the house. I want to keep it, but I am thinking of cutting it down to about a foot and letting it grow again. When is the best time to do this? Should I do it before it buds or after it flowers? Thanks for your help. I enjoy your column. Think spring! (Oakes, N.D.)

A: Brace yourself for a major change in appearance. Cut it down before the plant breaks dormancy this spring, which is sometime in March. The temperature should be at least above zero by then!

To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail

NDSU Agriculture Communication

Source:Ron Smith, (701) 231-8161,
Editor:Rich Mattern, (701) 231-6136,
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