Submitted by: agcomm, Thu Jul 31 10:49:57 1997 Hortiscope Ron Smith, Extension Horticulturist North Dakota State University Q. Please send me information on my hoya plant. I transplanted it a year ago but some of the leaves seem to fold up. A sample is enclosed. Thank you. (Roseau, Minn.) A. It is most likely that your hoya is still responding to being transplanted, as it is not one of their favorite things to happen to them. Q. Whenever I need advice on anything that grows in the ground, I think of you as I value your expertise. Please tell me how to get rid of the cattails growing in a ditch. (Tulare, S.D.) A. It is hard for me to come up with a way of eliminating cattails, as they can be a source of food for both us and the wildlife. As long as the ditch continues to fill up with water, cattails will recur. Try the herbicide Rodeo, an aquatic, non-crop, non-selective herbicide. It should work. Q. In a previous column, you recommended that Miracle-Gro be used on arborvitae. We have both products: Miracle-Gro and Miracid. The recommendation for evergreens is to use Miracid. Please address this matter in a future column. We have benefitted so much from the information in your columns and take your advice as "gospel" the good news so please help us in this one also. Thanks. (Lisbon, N.D.) A. Miracid is used where soil acidification is needed. It does this gradually, by the action of soil microorganisms breaking down organic compounds. The length of time required to produce the acid reaction depends on the amount and frequency of application of the product, along with soil type, temperatures and moisture conditions. Like its "mother product" Miracle-Gro, there is no danger of harmful residual buildup and certainly in our region, no danger of making the soil too acidic. Miracid is often recommended where iron or other trace element chlorosis or deficiencies are noted in a crop or planting that are not corrected by the usual methods. Like Miracle-Gro, the product's nutrients are quickly utilized by the plants through foliar application hence the quick but non-leggy response. I didn't mean to neglect this important product to gardeners. I am fortunate enough to not have chlorotic plants and have found Miracle-Gro to give me the results I want. Q. I am sending a few leaves off of our tree. It has been doing well until now. The leaves are curling up and turning inward, and I don't know what could be causing it. Could you tell me what kind of a tree it is and what is causing this? I would like to know if there is anything we could spray it with. Enjoy your column very much. Thank you. (Mayville, N.D.) A. I am sorry, but you did not send enough of a sample for me to positively identify it. If you would send me another sample with leaves attached to a branch, then I could likely identify it for you. Concerning the spots on the leaves, it appears to be a combination of factors: past or earlier feeding of an insect (likely leafhoppers), environmental stress and some edema from possibly water-logged conditions in the soil. Q. Enclosed is a clipping of the diseased end and one that isn't. Is it a cut leaf maple? What do you advise to prevent further disease? It was planted 40 years ago. (Hope, N.D.) A. Your sample is from what is known as the Amur Maple, Acer ginnala, which has "cut" leaves. A good tree. Unfortunately, your tree appears to have the symptoms of a virus, TbRSV (tobacco ringspot virus), a disease often associated with trees in decline, which in the case of your maple, could be possible after 40 plus years. I suggest pruning the affected branches out and fertilizing the tree with Miracle-Gro to help improve plant vigor. Perhaps you can slow or temporarily stop the spread of this disease on this beautiful tree. Q. I would like to know more about my apple tree. The snow broke it down so bad last year. If I cut it off to where it is damaged, will it regrow? (Edgeley, N.D.) A. Yes, I have found that if the tree is healthy it will regrow. Do the pruning quickly! You are running a little late to do it this year. Q. All of your information in the Sun Country has been very informative to me. I hope you can give me a good report on what is happening to my pear tree. On the east one third of the tree the leaves are all turning yellow. There are pears on them. The rest of the tree has dark green leaves. Very healthy looking, the tree is about 25 years old, about 50 feet tall, has been very fruit bearing. It produces anywhere from 2000 to 4000 pears if I count small ones. Last year it had about 2000, larger than usual, and very sweet and juicy. I give it four fruit spikes every spring. It is next to my apple tree, raspberries and strawberries. Hope you can give me an answer to this. Thank you. (Bowdon, N.D.) A. First of all, congratulations on having what could be the oldest fruit bearing pear tree in our region! Next, the inter-veinal chlorosis has me puzzled, but I can suspect a couple of things that only you may know. My first suspicion is possible herbicide drift or movement. It is not a phenoxy type damage, but your description makes me think it is some type of other herbicide damage, with the rest of the tree appearing so healthy. My second guess would be a possible canker or borer on one of the scaffold branches. If you can find any evidence of either, then the branches need removal. My dollar would be on my first assumption, as everything else is too good looking! Q. Can you tell me what ails my tomatoes? I have sprayed twice with Mancozel plant fungicide. This affects nearly all of 100 plants. It seems that the bush tomato is less affected. (Lisbon, N.D.) A. Your tomatoes are showing typical symptoms of phenoxy herbicide damage. It could be the result of drift from adjacent field or turf applications, or residual in soil or mulch. ### NDSU Agriculture Communication Source: Ron Smith (701) 231-8161 Editor: Barry Brissman (701) 231-7866