Hortiscope

March 23, 2006

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Could you tell me how far away I should plant an oak tree from a water line? (e-mail reference)

A: If the water line doesn't leak, you don't have to worry about where to plant it. Just don't hit the line with your shovel or backhoe. If the line is leaking, then plant the tree as far away as possible.

Q: I am new to North Dakota. I have been trying to find trees that I can plant that grow fast and will be an excellent windbreak. I moved here from a state where fences are all that you see, so I do not want to put up a snow fence. I am on a lot next to a highway and will appreciate the privacy. (e-mail reference)

A: Welcome to North Dakota! It is always great to greet a newcomer. Of course, I am delighted to help you. Go to the NDSU Web site at www.ext.nodak.edu/extpubs/trees.htm for publications dealing with windbreak establishment and care.

Q: We have a large maple tree in our front yard (not sure what kind). One of the branches is shedding bark. I'm wondering if it’s normal or if I should cut that branch off. The rest of the tree seems fine. (e-mail reference)

A: Normally, as silver and paper bark maples mature, their bark becomes exfoliating. But to have it show up on one branch is not common. I wouldn't cut that branch off if the tree has a normal foliage appearance. Examine it closely to see if there is any evidence of borer or bark beetle activity, which would be manifested by frass and sawdust mixed together, along with some small holes in the branch.

Q: Several years ago I planted snow-on-the-mountain in my flower beds. It has now become very invasive. I wish to eradicate the plants because I am getting tired of spending the summer trying to keep ahead of the runners. Any suggestions would be appreciated. (Fargo, N.D.)

A: The only solution I can think of is to use a glyphosate – RoundUp - this spring as new growth begins. It will take repeat applications, so don't lose patience.

Q: I have a miniature lilac bush in front of my porch. It is bare on the side of the porch. I would like to cut it down so it would renew itself. My neighbor told me to cut it down in March. She mentioned it would come back without the bare spot. I'm just not sure how far back I'm supposed to cut it. I don't want to kill it. (e-mail reference)

A: In this case, your neighbor is correct. Cut the bush back to short stubs (about 6 inches long) and you should get a flush of new growth this spring, but the plant will not bloom. That will happen next year.

Q: We've recently purchased a home with a willow tree that was planted too close to the house and water lines. What is the best way to kill the root system once the tree is removed? (e-mail reference)

A: I would have the arborist also grind the stump out. Ask to have the tree taken down about two weeks after it has leafed out. Then have the arborist grind the stump down below ground level. This way, the tree will have expended much of its stored energy with the spring flush of growth. Any sprouts that grow can be controlled as broadleaf weeds by applications of a herbicide containing dicamba.

Q: My father-in-law has an apple tree more than 100 years old on his farm in northeastern North Dakota. If possible, he would like to preserve it using roots, but is not sure how. He and a neighbor attempted some grafts, but were not successful. Shoots emerge from the base of the tree in the spring. Can the shoots be used to grow a new tree? (e-mail reference)

A: There is a propagation technique called "stooling" that would work very nicely on those sucker sprouts. Here is a description of how to do it from a plant propagation reference. Notch the base of each stem and then mound soil around the base of the plant so that the notches are well covered. Wait a year or two before severing the rooted stems from the parent plant (blueberries, currants, gooseberries, hazelnut shrubs, Juneberries). It also can be done on apple stems that arise around the base of the tree. I would encourage using a mixture of 50/50 sand/peat moss for optimal root formation. Keep the mixture damp. Once roots form, which is usually by the end of the growing season, cut the stems off and plant them where you want. It couldn't be easier.

Q: I have a way to control potato bugs. As soon as the potatoes start coming up, I plant a few marigolds here and there around the potato plants. I haven’t had any bugs for three years. (Binford, N.D.)

A: Thank you for writing! I'm glad this technique works well for you. My success has been inconsistent, although I keep trying!

Q: Is there a proper way to move fig trees? I have one that is several years old and is well established. I want to move it to a new home. I was told that fig trees don't even like to be moved across the room! Is there a way to move it without putting it through stress and hurting it? I enjoy your articles every week. (Starkweather, ND)

A: Get some old, dry cleaning bags and double-wrap the tree. Try to move the tree when the weather is as mild as it is going to be. Place the tree in an area of the new home that is as environmentally close to where it presently sits. Be sure the plant is well-hydrated before wrapping and moving. Uncover the tree as soon as possible after moving it. There is no guarantee, but this is the best recommendation I can come up with. If it starts dropping leaves at the new location, don't panic. Allow the tree to go through the process of readjustment. It will releaf in four to six weeks. Treat the tree as you normally would through the whole process.

Q: My mother gave me a beautiful amaryllis bulb for Christmas. Now my mother-in-law is jealous. She and I share plants and flowers through the year. I was wondering if there was any way to split the bulb. I have one bulb, but the bulb has six to nine flowers on three different stems. I know the seeds will produce, but that will take years for them to grow and germinate. (e-mail reference)

A: Nothing worse than a jealous in-law! Allow the plant to go through the blooming cycle and the foliage to remain through the summer. Bring it inside before the first cold snap in the fall. Allow the plant to dry down to mimic its native conditions. When all the foliage is dead and before you repot it again in 30 to 45 days, take the bulb out of the pot. There should be three to four small bulbs around the side of the mother bulb. You can separate those and give them to your mother-in-law. Both of you probably will have to wait a couple of years before you get any flowers. If this doesn't please her, just give it to her. Better to have peace than animosity in the family. You can always get another plant.

Q: I’ve had a cyclamen for more than a year. It was blooming beautifully when I bought it. I thought the plant was getting too big for the pot, so I transplanted it. Although my plant continues to bloom, it is spindly. The stems on the leaves are long and droop over the edges of the pot and the blooms do the same. Do you think my plant needs a rest? Could I cut the plant back, remove all the leaves, let it sit where it is now and not water it for 90 days? It seems that ever since I have had the plant, it has always had blooms and new leaves growing. When is a good time to give the plant a rest? I don't want to loose the plant, but it is looking straggly. (e-mail reference)

A: The plant is literally exhausting itself. It also sounds like it is light deprived. Once you have given it the needed rest, begin growing the plant again with the aid of artificial light.

Q: I have a miniature orange tree that I have had for three years. When I bought the tree, it had oranges. Since then, it has not produced any new oranges. The tree has grown, flourished and occasionally flowers, but has not produced oranges. After flowering, there are tiny green buds, but then they fall off. Will my tree ever produce oranges again? (e-mail reference)

A: Try a little tree doctoring when it is in flower. Snap the branches with your index finger to shake the pollen onto the pistil. It sounds like the flowers are not getting fertilized so the fruit cannot develop. This should correct the problem.

Q: I enjoy reading your column and am interested in planting blueberries, sea orange (from Siberia?) and lingonberries. My plan was to dig up a good-sized garden area and amend the soil with peat moss and aluminum sulfate. My concern is the use of this aluminum compound. Is there any danger with using it and then consuming the resulting berries? Also, do you have any advice on the planting and care for these acid-loving plants? (West Fargo, N.D.)

A: Pure sphagnum peat moss and fertilizing with an acid-forming fertilizer, such as aluminum sulfate, will provide the crop you want. In naturally occurring acid soils found in the northeastern part of the U.S., aluminum is a common element. Getting the soil too acid will result in acid toxicity to the plant, not the consumer. Aluminum is not used in plant metabolism.

Q: I have a jade plant I bought at a garage sale five years ago. It's been doing great and I never have repotted it. It became obvious to me in the last year that it was time for a bigger pot. When I went to remove the plant from the old pot, I noticed the pot's top was narrower than the bottom and the plant was stuck. As a result, some of the roots were torn from the plant. The root ball has been torn in half horizontally. I finished repotting the plant and put it back in the same spot where it has been thriving for the last three years. Is my plant going to die? Is there anything I can do to help it? I'm very worried about it. (e-mail reference)

A: I doubt it will die. Jade plants are tough in spite of all the problems people seem to have with them. You obviously don't have such problems, so keep doing what you have been as far as cultural practices go, but don't overdo it by applying too much water or fertilizer.

Q: I am planning a “living wall” around a large residential subdivision in Moorhead, Minn. The purpose of the plantings is to create a natural barrier to traffic noise and adjacent developments (replacing typical cedar fences). We tentatively are planning on planting approximately 400 Colorado blue spruce, 250 maples and 350 miscellaneous shrubs. I have heard concerns regarding Colorado blue spruce diseases, but have found they are much less expensive than similar species. I would appreciate any advice about our plant species selection. Also, I would appreciate advice on how far apart we should plant the trees, while still allowing the living wall to be an effective barrier. (e-mail reference)

A: Go to my Web site at www.ext.nodak.edu/extpubs/trees.htm and then scroll down to publications EC 1764 and EC 1767. The publications discuss windbreak plantings in detail. The information should be applicable to what your intentions are. If you have any questions after looking over the publications, get back to me.

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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

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