NEWS for North Dakotans
Agriculture Communication, North Dakota State
University
7 Morrill Hall, Fargo, ND 58105-5665
April 22, 1999
Hortiscope
Ron Smith, Extension Horticulturist
North Dakota State University
Q: Is there a variety of tree that can be grown in a damp area in our shelterbelt that might have some saline seepage? We planted a bunch of trees, but they aren't doing very well there. (Glen Ullin, N.D.)
A: You have one of the most difficult situations to work with! The most salt-tolerant species may or may not make it, but if you are willing, select from Tamarix ramosissma, buffaloberry, silverberry, Russian olive, sea buckthorn, skunkbush, sumac and freedom honeysuckle. All are noted for their ability to withstand saline conditions with Tamarix leading the way. Try that one first and if it doesn't survive, forget the others!
Q: The enclosed twig is from one of our three Canada red cherry trees. All of them have this fungus attached to them. Could you tell me what it is and what to do to get rid of it? (Felton, Minn.)
A: Thanks for the excellent sample of Apiosporina morbosa, black knot fungus. These knots eventually girdle and kill the branches. The infection perpetuates itself in the spring during periods of rainy weather. To control, prune out all visible knots immediately and spray the tree with lime sulfur if the buds have not already opened. After bud-break, spray the tree with a Captan/benomyl mixture.
An additional note: This is a very destructive disease often disfiguring the tree to the point of aesthetic liability. You might be better off in the long run, to take this tree out and replant with something else. I've seen too many cases where control attempts turn out to be a losing battle.
Q: Where can I purchase lime-sulfur like you have recommended? (Maple Plain, Minn.)
A: At any major garden center or garden supply section in a major retail store.
Q: I have yellow rose bushes that have been growing in the same spot for 30-plus years. I do not know the name of the bushes, but they bloom only a couple of weeks in late May or early June. I want to move them to another location, so I am wondering when the best time is to do this? I also need to know how to get the weeds out of the bushes when I move them. I also have an upright arborvitae bush (I think that is what kind of evergreen it is), and I am wondering if it is safe to cut off the branches that have been bent over by wet snows. (Salem, N.D., e-mail)
A: Dig and transplant your roses as soon as possible, before new growth breaks. Cut them back heavily, anywhere from one-third to one-half their original length. Make clean cuts with pruners on the root systems when you dig out the bushes. Roses like to be pampered! Move them into soil that has been well prepared with compost and they will thrive much better for you than if you made no soil prep at all. As far as weed removal goes, I'm afraid the only way is the old fashioned way—removal by hand as you are digging them. You might want to work in a rose fertilizer like 10-10-10, or simply water them in with a Miracle-Gro solution.
Rather than cutting your evergreen branches off, try tying them up to a stake or broom handle with some rag cloth for about three to four weeks to see if that gets them straight again--it usually does. If you have no choice but to cut them back, do so this spring, and try to shape them up to your desire later.
Q: I would like to know why I have not been able to grow corn for about the past four years. I can only get four sprouts from two packages of seed. Previously, I have had great success. I have had the same garden spot for 20 years and rotate my crops religiously I also have fertilized with urea, but not consistently. (Lansford, N.D., e-mail)
A: Why won't your corn grow now where is has grown in the past? Low sunlight? Too cold or wet? Birds get the seed? Cutworms? Old seed? Late frost? Herbicide residue?
I cannot think of any other possibility than what I've listed here. Why not try a different variety? There are several great ones out there.
Q: Enclosed you will find some bark from a hackberry tree. The tree seems to be dead, with the bark breaking away. I saw some red beetles on the tree. The beetle kind of looked like a grey potato bug. Can you tell me what is wrong with my tree? (Lisbon, N.D.)
A: Thank you for the good description of the insect you found on the dead tree. Most likely it was the red-headed ash borer, as they are commonly found on ash, oak and hackberry trees at this time of year. There is no registered spray for this insect. The best thing to do is cut the tree down ASAP and get it off the site. I suggest a close monitoring of the remaining trees, and expend any effort needed to keep them healthy. Borers are attracted to stressed, weakened or dying trees. Healthy trees are seldom attacked.
Q: What is the secret for transplanting bur oak? I have tried three in the last two years without success. (Rugby, N.D.)
A: The secret is that bur oaks don't transplant! Their taproot system is literally destroyed when they are dug up. Try gathering acorns and planting them where you want them. They need no fertilizer.
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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.
Source: Ron Smith (701) 231-8161 ronsmith@ndsuext.nodak.edu
Editor: Dean Hulse (701) 231-6136