NEWS for North Dakotans
Agriculture Communication, North Dakota
State University
7 Morrill Hall, Fargo, ND 58105-5665
June 4, 1998
Ron Smith, Extension Horticulturist
North Dakota State University
Q: I am writing about care and culture of violets—how soon to repot, when to bring them home from florists. Why do they, after awhile, grow heavy stems, neck type? How about water? When I don't have rainwater, I have to use well water. I boil it because it does have minerals. Also, gloxinias—more or less same questions. How and when to store bulbs until early spring? (Deering, N.D.)
A: Basically African violets and gloxinias need the same care. If they become unattractive with age, they are easily propagated from leaf petiole cuttings.
You are being too fussy with the watering. Boiling does not correct a mineral problem, it tends to concentrate them. I suggest using distilled water when rainwater is not available.
Q: I have had my hibiscus plant for two years and this last winter I repotted it and enjoyed a burst of new growth of the plant. Then recently it started dropping yellow leaves. I sprayed it with insect spray, but it just got worse. I will probably lose it but still would like to know what the problem is. (Perham, Minn.)
A: I could not detect any pathogens on the sample you sent. I suspect the plant needs to go through a dormant period. Allow the plant to defoliate (don't keep watering it like you normally do), and cut the stems back to 6 inches from the base of the plant.
Summer it outdoors. After about 4 to 6 weeks of dormancy, return to normal watering. Fertilize monthly. It should recover.
Q: What is wrong with my birch trees in my yard? As soon as they leafed out this spring the leaves curled. When I unwrapped the leaves I saw little bugs in each curled leaf. I'm sending along a sample. Please advise me what I can spray on my trees to save them. They also have small dead branches throughout the tree and small ripples under the bark a few places on the trunk and limbs. What is this? (Perham, Minn.)
A: There are a few things wrong with your birch tree that have nothing to do with the bugs you enclosed.
The most disturbing thing is the herbicide damage. Apparently someone sprayed a 2-4,D type of herbicide (like Trimec) over the root system to kill dandelions and other broadleafed weeds to such an extent that the material was taken in by the tree. The curled leaves and petioles are a direct result of this herbicide use.
Secondly, the bumps under the bark are likely borer tunnels. Birches are susceptible to attack by Bronze Birch Borers when they are stressed. It now becomes a question of what will kill the tree first—the herbicide uptake or borer activity?
At this stage, there is little you can do except to see if the tree is able to pull out of this with a little help on your part. Keep it watered and fertilized, and prune out the dead branches.
I wish I could give you better news. Birches are among my favorite trees!
Q: I have this cedar tree in my yard. I am sending you the things that are growing all over the tree. Please let me know what they are and how to prevent them. (Havere, S.D.)
A: Those growths are the fruiting bodies of the cedar-apple rust fungi.
Your junipers are acting as the alternate host to re-infest an apple, crabapple, Juneberry or mountain Ash. The pest control is what you just did—pick them off. That interupts the life cycle of the disease.
Once broken, the disease is no longer a problem. Another alternative that isn't very likely is to remove all the junipers or members of the apple family, to break the cycle.
Q: I own an empty lot across from my house and just finished planting about 70 bare-root trees there. My problem is with dandelions. I sprayed last spring and fall, but of course it is impossible to kill them all. I don't dare use 2,4-D with these small young trees. Do you have any other suggestions? (Maddock, N.D.)
A: If you can direct your spray away from the foliage of these young trees, Roundup would do an excellent job killing only the plants whose leaves are hit with it. It has no soil activity and will not be taken up by tree roots.
Q: We recently bought a home in Pelican Rapids and one maple tree (8 feet) has this on it, and is getting worse. Our other maple has nothing on it. We have no idea what it is or what to do about it. Please advise! (Pelican Rapids, Minn.)
A: Your silver maple has bladder galls, one of the more famous galls caused by mites. Their form and color, as well as their high population on maple leaves, cause much concern for homeowners. These mites migrate to the unfolding leaves where they begin to feed, causing the pouch-like galls.
To make a long and interesting story short, you have nothing to worry about as they will not harm the tree, and there is nothing recommended for their control.
Q: Enclosed find a couple of leaves from my plant. I've had it three years. Can you please tell me its name and the best way to take care of it? Every so often the bottom leaves turn yellow and fall off. It's about 4 feet tall. (Fargo, N.D.)
A: The plant sample you sent looks like a Dracaena marginata `Variegata,' a very attractive plant with grass-like foliage.
These are usually trouble-free plants. My examination of the sample you sent showed no pathogenic activity. I suspect that what you are seeing is normal leaf senescence, or die-out. As long as the rest of the plant looks healthy, I wouldn't worry about occasional leaf decline.
Q: These hackberry and linden leaves are from trees planted last year. They were translucent, yellow and puckered. (Mohall, N.D.)
A: The samples you sent me showed extensive herbicide damage (likely 2,4-D). They are likely not to survive.
Q: Enclosed is a fern peony five or six years old that is located on the south side of the house. The buds have the same black edges. This has happened last year and this year and I do not think it was caused by frost. (Carrington, N.D.)
A: The peony buds are infected with a fungal disease known as botrytis, or grey mold. This is brought on by wet weather, poor drainage, splashing water or too much shade, or all of the above. Be sure affected blooms are removed immediately and also the frosted debris in the fall. Spray the emerging shoots in the spring with chlorothalonil or benomyl. Repeat a couple more times—at five and then 10 days. If that doesn't help, dig the plant up and move it to a new site.
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Source: Ron Smith (701) 231-8161
Editor: Dean Hulse (701) 231-6136