NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
September 9, 1999
Ron Smith, Extension Horticulturist
North Dakota State University
Q: I like trying new things in my garden, so I let some of the tops of my onions go to seed. Can I plant that seed and will it produce regular large onions or not? (Emery, S.D.)
A: You certainly can! It will take a couple of years, but it is fun to do. Enjoy!
Q: Our concord grapes have these little white bugs on them. How to I get rid of them? (Montpelier, N.D.)
A: The white insects are likely mealybugs, a piercing, sucking type that in high enough numbers can debilitate plants. The flying ones could possibly be flying ants--going after the honeydew secreted by the mealybugs. While there are effective natural parasites, you cannot afford the time at this point, or you will lose your crop. I suggest a spray with Sevin, making sure you have covered undersides of the leaves.
Q: I have a bush that appears as if it is being attacked by two different pests. One is a small caterpillar that forms a small compact tent, and the second pest almost looks like a tiny slug. Are they different stages of the same insect? What are they and how do I control them? (New Town, N.D.)
A: You are seeing the second generation of "pear slugs," which are not slugs at all, but the larval stage of sawflies, which are slightly larger than the standard housefly. Right now, cut off all affected branches on your cotoneaster and burn them. Next spring after leaf-out, spray with carbaryl (Sevin) or malathion. Repeat in 10 to 14 days. That should solve the problem.
Q: I see an unusual berry plant growing in great numbers along sloping sides of a couple of overpasses on I-29 in the Grand Forks area. The berries hang in large clumps on the underside of plants 2 feet tall. (Grand Forks, N.D.)
A: The fruit is of the Blake chokecherry--Aronia melanocarpa. It is safe to eat, although one has to wonder why the birds don't go after these berries like they do my apples, Juneberries, tomatoes etc!
The Blake chokecherry is widely distributed from Nova Scotia to Florida and west to Michigan in natural habitats. It is completely hardy in North Dakota, but the flowers are not showy and the species tends to sucker, leading to large communities. Cultivars are available.
Q: Can you tell me what is the matter with our apple tree? There is a heavy brown web on the branches and the foliage has died on those particular branches. Something also has been spinning a web around the apples and eating the fruit.
Also, our 30-year-old spruce trees are losing their needles this summer. Do we have some type of mineral deficiencies? (Page, N.D.)
A: You must be seeing the work of the fall webworm. If it makes the nest of webs over branch ends, that's what it is. Apples are high on its culinary list! The best control is to cut off the branch ends that have the webbing and burn them. Next spring, initiate a spray program as if you were controlling codling moth, using products containing carbaryl, diazinon or malathion. That will take care of any new interlopers!
It sounds like the spruce have a disease known as needlecast. You can control the further decline of the trees with a spray program using Bravo in June and July.
Q: Can you tell me what is wrong with my blue spruce? It had a lot of healthy new growth, but then when the weather was over 100 F, the new growth started turning brown. It moved from the bottom of the tree upward. (Watauga, S.D.)
A: I think your tree will be OK, as long as the same weather pattern doesn't repeat itself!
Q: Previously I wrote to you and you diagnosed my strawberries as having angular leaf spot. We tilled some of our plants under before we realized that it is carried over in the soil. What can I plant in this spot now that won't contract this disease? I've been thinking about asparagus, but I'm not sure. (New Salem, N.D.)
A: Asparagus and/or rhubarb sounds like a winner to me! These two are fairly tough and dependable.
Q: I have several questions that came up this growing season:
1. Our new house came with three overgrown and neglected crabapple trees, the pruning of which triggered what appears to be fireblight. I optimistically and lovingly planted and pampered an expensive new rosebush, not realizing until later that roses are related to apples. It turned brown and died within several weeks. Is there any way to grow healthy roses in our yard?
2. We collect rainwater from the roof and use it for houseplants as well as the garden. Could the blight bacteria be in the rainwater? My kitchen herbs are blackening, and the impatiens outdoors are also showing brown leaves.
3. We replaced all the house's old leaky windows with new ones having what they called "low-E" glass. They're wonderful for keeping the winter warm and the summer cool, but I wonder if they block too much of what our houseplants need of sunlight. They seem to get pale and leggy even in the sunniest windows. (Palermo, N.D.)
A: You ask some very good questions!
1. The fireblight bacterium is airborne and therefore present in rainwater. Being a bacterium, it can enter microscopic openings, which plants are full of. Concerning your rose passion, try it again only this time plant in another location, avoid water splashing on the foliage, if possible, and keep it sprayed with a multipurpose fungicide spray or a fungicide containing triforine. Lime-sulfur and Daconil 2787 are two other examples of the many fungicides available for roses.
2. Has your roof been re-shingled in recent years? Could be some chemical toxins coming off that. The fireblight bacterium doesn't infect all plant material, of course. You could also be getting Pythicum fungus started on your plants.
3. You bet! I don't know the range of light that is being blocked, but it has to be within the range that helps produce chlorophyll. There are "spot plant lights" which you can use to overcome this.
Q: Can you tell me what is wrong with my tree? The leaves turn brown, curl and then the whole tree dies. (Linton, N.D.)
A: Your tree has anthracnose symptoms, but that alone is rarely fatal. It usually causes defoliation in the early spring, if at all. I think you are witnessing a number of problems: the anthracnose fungus; a root-rot disease; and a soil-borne disease known as Verticillium wilt, which can very effectively cause rapid death of a tree.
Q: I have a nice tulip area in my garden. I noticed this fall there are tulip bulbs or corms on top of the ground. Why is this happening and what should be done with them? (e-mail)
A: Those are likely the "seeds" from the flowers of this past spring. You probably didn't dead-head them all after flowering, and some set seed and fell to the ground, did a little growing on their own, and are now "bulblets." Plant them about 2 inches deep, and they will come up next spring and produce some small flowers, possibly. Try it, see what happens and let me know.
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 email@example.com .
Source: Ron Smith (701) 231-8161
Editor: Dean Hulse (701) 231-6136