NEWS for North Dakotans
Agriculture Communication, North Dakota State
University
7 Morrill Hall, Fargo, ND 58105-5665
July 2, 1998
Ron Smith, Extension Horticulturist
North Dakota State University
Q: I was wondering what is wrong with my cranberry bushes (2 years old). I started with four and have only two left. The leaves seem to curl. I have sprayed them with daconil, but it hasn't really helped. They are on the north (somewhat northeast) side of the house and under a roof so they don't get much sunlight. (Walhalla, N.D.)
A: The curling leaves are caused by aphids feeding. Daconil is a fungicide and is ineffective against aphids. I suggest spraying your viburnums with Orthene now and early next spring as the leaves unfold. It is both a contact and systemic insecticide, so you should get effective control.
Q: For the last two years my wild plum tree has been producing an airfilled fruit-like growth. I see it's happening this year too. Very few real plums are on. What can I do to stop this? (Leola, S.D.)
A: Your plum is likely manifesting a fungal disease known as "plum pockets" (Taphrina species).There is also a chance it is caused by chokecherry midge. Check the fruit to see if any maggot activity is present. My bet goes with the plum pocket fungus.
This disease is relatively easy to control with good sanitation and by spraying with lime sulfur when the trees are dormant in the early spring or late fall. Be sure the buds have not yet swollen (spring), and spray to cover tree completely. Be sure to pick up fallen fruit and any remaining on the tree before new growth begins.
Q: This is the third season for my flower garden. I've got wildflowers and various other perennials growing. This area was never a flower area before. This season this plant showed up, and I've been told it is strawberries. There are two other plants a few feet away. I do not want strawberries as I'm told they spread and are hard to get rid of. Can you help with my sample? (Davenport, N.D.)
A: Strawberries hard to get rid of? I'm sure some strawberry growers would like to believe that! But, not to worry, you have a genuine weed known as either Norwegian cinquefoil or rougle Cinquefoil (Potentilla norvegica). A pest, but not a bad one. Simply dig it up by hand if there are but a few, or spot-spray it with Roundup if there are many.
Q: I have a tree in the yard which has been there 50 years or so. In looking at an article that compared the horse chestnut with the Ohio buckeye, I thought it was a horse chestnut. I'm enclosing the mature seed, which is a pretty reddish brown nut inside a prickly covering. Can you clarify what it is by looking at the samples? (Finley, N.D.)
A: Piece of cake! The difference between the Ohio buckeye leaf and the horse chestnut leaf is like the difference between a Ford Escort and a Ford half-ton pickup. Same species, but the difference in size is obvious enough that measurement is not necessary.
Ohio buckeyes are hardy into Canada. Horse chestnuts are found across the lower Midwest—Ohio, Indiana, Illinois, Iowa, South Dakota, etc.
Everything except the fruit is larger on the horse chestnut—overall size, leaves and buds.
Q: I've enclosed infected samples of ivy and ferns. I've sprayed them with soap suds, but evidently I'm not getting the bugs. Could you tell me what I could use to get rid of the bugs? (Tyndall, S.D.)
A: Your ivy foliage is very undersized and in need of some fertilizer. Repot, and sprinkle a couple of pinches of fertilizer. You should see some response in two to three weeks or less.
Obtain Safer's Insecticidal Soap to control the aphid and mite problem on your plants. Household soap does little good. It wouldn't hurt to rinse the foliage of your plants through the summer with tap water. That, too, will help control insect buildup and produce healthy plants.
Q: About four years ago I got this columbine seed, and the plants were a plumish red with a cream center. This spring little ones are coming up all over, and they started to bloom in a variety of colors. My question is, will they come back next year in the same colors, or should I take the seed off and save it, or is it just a fluke of nature and I'll end up with the first color back again? (Litchville, N.D.)
A: You have experienced what is known as open pollination. In other words, nature, helped along by wind and insects, crossed the Columbine flowers for you to produce very high germination rate seeds. Next year should be pretty much the same. A good rainbow of colors. Enjoy!
Q: Do I have a serious problem with the enclosed branch from my snowball tree? Is this a disease? Can it be controlled? (Tuttle, N.D.)
A: Your hydrangea sample was "buggy" with green peach aphids and the larvae of hydrangea leaftiers. I suggest an immediate spraying with Orthene or a similar systemic to control the population somewhat. Other than that, the plant appears to be free of disease symptoms.
Q: Enclosed are flies that are eating the leaves on my hackberry trees. What can I do to get rid of them? (Barney, N.D.)
A: The flies you included were interesting, but had nothing to do with the leaf damage on your hackberry. They do not have chewing mouth parts.
The damage appears to be that of the larvae (caterpillar) of the empress butterfly—which is now gone. Spraying at this time would be futile, unless their physical presence can be ascertained. Thanks for the good sample.
Q: Enclosed is a pest weed sample. I have tried to get rid of it with 2, 4-D but haven't had much luck. What is it, and how do I treat it? (Lidgerwood, N.D.)
A: You need something a little stronger to get rid of the black medic, Medicago lupulina. Too bad we cannot make it a desirable ornamental.
Try Trimec or Confront. Both are available at retail outlets. We've had good success with them in the past. Thanks for the good sample.
Q: I have a tuberless begonia. I took off some slips, rooted them and put them in a pot. They appear really healthy, but they do not seem to flower. (LaMoure, N.D.)
A: Try not being so nice to them! Allow them to become potbound and a little starved. Then give them the morning light, and they should flower for you.
###
Source: Ron Smith (701) 231-8161
Editor: Barry Brissman (701) 231-7866