NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
June 8, 2000
Ron Smith, Extension Horticulturist
North Dakota State University
Q: I have moss that's growing on the ground on the north side of my house. How do I kill it? Someone told me the only thing to do was to take the top layer of soil off, put new soil in it's place and then plant a shade grass. Is there anything else I could do? Like apply a fungicide? (LaMoure, N.D., e-mail)
A: Moss will likely form again. You need to improve the drainage of your soil and reduce the watering in that area. A site that supports moss is likely to not support grass too well. Try creeping red fescue, or rough bluegrass if the area is continually moist. The rough bluegrass is the best one for those conditions.
Q: A neighbor at the lakes has a black substance on her trees and they appear to be weeping. Would this most likely be sooty mold or a canker? I am going to be looking at them this weekend. Someone at a garden store told her to use Orthene before Memorial Day, which leads me to believe she has a bug problem and sooty mold as a result. (Detroit Lakes, Minn., e-mail)
A: The black substance is most likely black knot, a fungal disease that hits members of the cherry species--Prunus spp. If she wants to save the tree, I suggest using lime-sulfur at a rate of 0.5 pint per gallon of water.
Q: We have nightcrawlers so prolific in our yard that we can barely walk across the grass without tripping. The lumps in the grass are everywhere. Is there anything we can do to get rid of the them? (e-mail)
A: First of all, I suggest renting a power rake and knocking down the mounds their activity has created. Then, apply Sevin at the label rate to control slugs. This will reduce their population by about one-third to 40 percent. If the problem persists, make a second application. By the way, nightcrawlers' activity is reduced significantly when we get into the hotter summer months.
Q: I have a question concerning my weigela shrub. It has been sprayed with diazinon by accident and it is killing all the foliage. Can I prune this bush extensively to save it or what can I do that may help? (Potosi, Mo., e-mail)
A: I don't know why diazinon would be killing your weigela shrub. But yes, cut it back hard, close to the ground to see if that will save it.
Q: My golden elder has many stalks/canes/trunks (I'm not sure what they are called), that are rotted off right at ground level. What caused this and will this tree live? It is about 15 years old and has been a beautiful tree, and I would hate to lose it. There are still several stalks left, but I know I took out at least half of them if not more. (Tappen, N.D., e-mail)
A: I have no idea what could be causing the stems to die. Try spraying it with lime-sulfur or Bordeaux mixture, which are broad spectrum fungicides and somewhat environmentally friendly. That should arrest whatever is causing the decline, I hope!
Q: Is there something we can apply that would kill the weeds in our strawberry patch but not harm the plants? (Esmond, N.D., e-mail)
A: There are several: Dacthal W-75, Devrinol 10-G, and E-2, Formula 40, Poast, Princep, and Prism.
Q: How do I take care of my dieffenbachia? (Montreal, Canada, e-mail)
A: I am growing a dieffenbachia in my office too, and in spite of my neglect, it seems to grow quite well! Your plant likely needs a little more energy in the form of fertilizer. I don't know what to recommend to you in Canada as far as a product goes, but if you can find a non-flowering houseplant fertilizer, that would be the one to use. It should have an analysis something similar to 10-10-10.
Also, be sure to turn the plant once a week to keep it from growing in a crooked manner. Water it a couple of times per week with tepid tap water, fertilize it once per month, and it should just about take care of itself from there!
Q: I am an organic producer in Divide County and would like to plant a large number of lilacs for erosion control. I am interested in starting or propagating the lilacs myself. Do you have any information on how to start lilacs from seed or the best way to propagate lilacs? If they can be started from seed, when is the best time to collect the seed? Can the seed be planted the year it is collected or does it need to go through a dormancy period? Can the seed be planted directly into the field or does it need to be started in containers and transplanted? Can lilacs be propagated by cuttings or by digging up suckers from established plants? If so when is the best time to do so? (Crosby, N.D., e-mail)
A: Lilacs can be produced from seed being planted in the fall to go through cold stratification. Germination is generally good. They can also be dug as root suckers anytime now and transplanted to the new site with some degree of success. It is past the best time for successful taking of lilac cuttings.
Q: In our courtyard in southern France we have planted one linden/lime tree three years ago (that's all there is room for). It was 12 years old and has grown well since then, but last year we detected dark scraggly tears on the bark going up the trunk, mostly about 1 to 2 inches long. In addition, we noticed two holes going into the trunk, higher up, which were deep and wide enough to put four fingers into.
At the place where we bought the tree, they suggested that it has worms, which eat the tree from the inside. We started to spray it once a month with a liquid insecticide with but stopped during the winter because some branches had become dry and brittle and broke off. Now the tree has produced large bright green leaves, so at least some of it remains healthy. But we don't know whether the spraying eliminates the pest.
What kind of pests befall such a tree? Someone visiting from the United States suggested to do a root treatment. What is that, and how does one do it? I can't very well supply you with a sample of a branch, but I would really appreciate hearing from you. (Geneva, France, e-mail)
A: Most likely your tree is being infested with a European cousin of the American plum borer, or the redheaded ash borer. Once they have infested the tree, it is almost impossible to control their damage. Eventually, they will destroy the entire tree.
My suggestion is to remove the tree and have it replaced with something available locally that is more site adapted. Local nursery personnel should be able to help you with a selection. Spraying the tree or injecting it with anything now is of no use. It is simply a waste of time and money, along with putting unnecessary pesticides into the environment.
Q: I have several blue spruces that I planted two years ago. They are about 7 feet tall and healthy but they have lost most of their blue! What can I do to get back the blue? I have heard that phosphate makes them become bluer. If so, how much? (Wichita, Kan., e-mail)
A: The "blue" of a blue spruce comes on in the spring with new growth. There are trees that are grafted to be "true blue" and are known as cultivars, such as Hoopsi and Kosteri. As far as I know, there is nothing you can spray on the tree to re-blue it. If your trees are tending toward green coloration, then they are likely seedling selections that would have normal species variability.
Q: My parents bought a Contorted Filbert tree last year, and they are now wondering what to do about the suckers coming out of the ground. From what I can gather, they are supposed to cut them. I would like to know the pruning methods and what not. I know that they know how to prune a tree. It's just that they like their little weird tree and don't want to kill it by pruning it too early or too soon.(Taylor, Mich., e-mail)
A: The Harry Lauder's Walkingstick, as your parents' tree is also known, requires almost no pruning EXCEPT for the suckers, which they will need to stay on top of. Perhaps the best way to manage suckers is with some landscape fabric (not plastic sheeting!) over the root zone. This will allow some air and water to enter but keeps the weeds and suckers in check--somewhat.
Other than that, simply cut off anything that is dead or broken, diseased or insect infested. That tree will have interesting characteristics as it matures.
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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