June 26, 2003

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Will a snowball bush grow in an area that has only morning sun? I'm afraid to move it because it is just starting to perk up. Any tips on what to do and how to keep it growing? (E-mail reference)

A: I love the term "snowball bush" because it has so many varied meanings. All shrubs that fall into that category will do well with just the morning sun, as long as the morning sun lasts about four to six hours. We get about six hours of morning sun at this time of year. If the plant is perking up, I would keep it where it is. If it appears to fade over time, the bush should be moved to a more sunny location.

Q: I need to move and replant a lace leaf Japanese maple tree. Can you give me instructions? Is it safe to replant now? (E-mail reference)

A: No to both questions. I would suggest moving it when dormant and by someone with experience in moving such trees. The ball size needs to be carefully calibrated to the aerial part of the tree, most particularly the caliper of the main trunk.

Q: My neighbor has some trees in his front yard that he calls Canadian cherry trees. They were planted two to three years ago and are approximately 10 feet tall. For the past few summers he has noticed a peculiar growth on some of the branches. They can get up to six inches long along the branches. Sometimes they drape all the way around the branches. He has been removing the affected branches but is wondering if this is the best way to treat the problem. (E-mail reference)

A: These are most likely Canadian red cherry trees. They are very subject to black knot, a fungal canker that can greatly disfigure a tree and eventually kill it. Removal and a vigorous spray program is advised. Removing affected branches won't often work because black knot is quite virulent and unrelenting in its spread. The fight is usually valiant but the tree owner invariably ends up the loser. He may want to capitulate and take the trees out now. The situation is only going to get worse with time.

Q: I have a small tract of land with three rows of trees on it. The rows are on a hill following directly down the hill. They consist of lilac, ash and caragana. They are about five years old and are five to 12 feet tall. When we till or cultivate, the water has a nice furrow to run down the hill so we are losing a lot of top soil. Do you have any suggestions? Should we plant grass or something else? On this same tract of land, we want to plant more trees but on the other side of the hill. We want to avoid erosion problems and keep native grasses growing. Can we plant trees without cultivating and tilling the ground? When we've done this, we ended up with nothing but weeds and lost all the good native ground cover. The tract of land is about five acres. Our goal is to have a grove of trees with fruit trees and the like inside. We don't have resources such as water and power to groom it daily. We have a water tank on an old truck. (Dickinson, N.D.)

A: You need to plant grass between the rows. I suggest a creeping red fescue like Cindy or Ruby. They are easily established, help to control weeds and will do well in the shade. I would treat the other land the same way. Kill everything with Roundup, mow down the dead growth, inter-plant your trees, then seed with the red fescue. You could use sheep fescue in place of the red. It will get about six feet tall and stop growing.

Q: I have a friend from Aberdeen, S. D. who would like to grow a moonseed vine (called yellow medicine here in southwestern Minn.). Could you suggest a source of plants or seeds? (Marshall, Minn.)

A: I don't know a source. This is a vine that produces poisonous fruits that resemble grapes and should not be grown where children are apt to consume them. Botanically, this plant is known as Menispermum canadense if you wish to pursue this further.

Q: Three years ago I planted two dogwood bushes of the ivory halo type. They were growing well and looking good until August of last year. One of the bushes turned a reddish color, had a few berries, then both bushes died. I could not see any bugs and the leaves didn't look like they were diseased. Any ideas why they died so suddenly? I didn't do anything different than I did in previous years. (Minneapolis, Minn.)

A: I could give you a half dozen guesses but that wouldn't help you. They simply could have been planted too deep which seems to be a common problem in the upper mid-western region of the country.

Q: I have a red maple that is ten years old. It has developed cracks on one side of its trunk, about five to six feet up from the base. It seems that, right above these cracks, branches are dying. The rest of the tree seems fine. What do you think is happening? (E-mail reference)

A: Those cracks are likely frost cracks that have affected the immediate branching area of the tree. Clean the wounds carefully back to the attached bark and allow them to be exposed to open air. Gradual healing will begin taking place. This fall, wrap the trunk in kraft paper right up to the first branches to prevent it from happening again. Red maples are prone to this problem until they develop a thick corky bark.

Q: We are losing evergreens and are wondering if you can help us. The trees vary in age from five to 15 years old. The needles turn pink, then brown and then fall off. We have checked for spiders and sawfly but didn't find any. These trees are sprayed every year with Malathion or Sevin. (Powers Lake, N.D.)

A: I'm certain the evergreens you are referencing are spruce. They usually suffer from needle cast, which is a fungal disease. Using an insecticide will not solve your problem. Spray them with Bravo, which is a fungicide. It will stop the disease from spreading. Spray in June and again in July. It will take about three years to bring it under control. Monitor the trees from then on to make sure it doesn't flare up again.

Q: I was told that marigolds keep mosquitoes away but I've also heard that they have to be the old-fashioned type because they are more pungent. Where can I buy old-fashioned marigolds? (E-mail reference)

A: It doesn't work so don't get your hopes up. I have seen squadrons of mosquitoes fly out of plants that are supposed to keep them away.

Q: I just got a call about a weeping willow that is bleeding. When the sap or fluid squirts out, it's white and makes a sound. It's a large tree and the bleeding is occurring about five and one half feet above the ground. I remember that bleeding was a problem with the Chinese elm. What might be happening and is there something that can be done? (Ellendale, N.D.)

A: It's just high internal osmotic pressure, which is nothing to worry about.

Q: Can I prune my amur maples to make them into an even hedge? How far apart should I have planted to use them as a hedge or privacy fence? (Braham, Minn.)

A: They can be used as a hedge but that destroys the natural beauty of these plants. You could plant them as close together as you want to quickly have privacy and closure.

Q: I have some nice large purple Irises. Two years ago I thinned them out because they were pushing out of the ground. Now those that remain come up green but do not flower. What might be the problem? (Moorhead, Minn.)

A: They just need a year to rebuild carbs for flowering.

Q: We have a nice sod lawn but it is being invaded by quack grass from a vacant lot next to ours. Is there a way to get rid of the quack grass and not damage the good grass in the process? Are there any products that really work? (Hazen, N.D.)

A: How I wish! There is nothing that is legal that will selectively take quack out of bluegrass. Your best bet is to learn to live with it by keeping the lawn fertilized, watered, and mowed high (about three inches). Death, taxes and quack grass are the three irrefutable certainties of life!

Q: We just moved to Moorhead in March. The lawn was in bad shape so we fertilized but missed a lot of spots. We fertilized again and now have a bunch of brown strips. What is our next step? (Moorhead, Minn.)

A: Give up! Don't do anything else except seek out a lawn professional to take care of your lawn. The grass will eventually recover.

Q: My wife and I noticed that there are two colored flowers on one of our lilac bushes. This is the first time we have seen this. Is this unusual for lilacs? (E-mail reference)

A: I would say it's unusual because I've never seen it before. It's probably a somatic mutation of some sort, which can only be reproduced via cuttings from that particular stem. Enjoy!

Q: My spider plant has not started producing spiderettes or spikes. How long does it take to reproduce? I got my plant before spring and have fed it just once, which was today. I think the way the creator created such a wonderful and beautiful plant is truly amazing. (E-mail reference)

A: "Where faith begins, worry ends!" Let's turn that around a bit and say it this way: "Stop worrying, as long as the plant is healthy, have the conviction that it will eventually produce spiderettes." Fertilize just once a month, keep it moderately well watered, give it ample light and sooner or later the spiderettes will begin forming.

Q: I would like to know where I can order or purchase some buds or plants to start a diamond willow patch? I'm buying five acres of land and thought it would be neat to try and grow some diamond willows. I want to make canes or other stuff out of the willows. (Williston, N.D.)

A: I am glad you asked the question because the subject has just about driven me nuts over the years. Here is the best explanation I can give you based on my most current knowledge. There is a diamond willow species and a diamond willow fungus. It is the fungus, not the species that produces the dark, artistic cankers used to make colorful canes and walking sticks as well as other decorative home furnishings such as lamps and candleholders. Diamond willow, the species, is Salix eriocephaia, or the synonym Salix missouriensis. To add to the confusion, Salix pulcha has the common name of diamond leaf willow. The diamond willow cankers are produced by fungus acting on various species of willow trees and not by the diamond willow species itself. I do not know where you can get the diamond willow species if that is still what you want. At least you now have the proper names to do some searching.

Q: I grabbed the wrong container and sprayed all my evergreen trees with Roundup. The evergreen trees are alphaviders. Will the Roundup kill the trees or just drop the leaves? I also sprayed some of the bottom limbs of my cypress tree. (E-mail reference)

A: I don't know if it will kill the trees. There isn't much you can do about it now except wait and see. You should know the results in about seven to 10 days depending on the temperatures where you live.

Q: I have a problem with a plant called nightshade. I used 2,4 D but that didn't work. (E-mail reference)

A: You should be able to do it in with Roundup. Use it during active growth before very hot weather sets in.

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