April 26, 2001

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: Can you tell me why the leaves are falling off of my maple trees? They turn yellow and fall down, but the remaining leaves appear healthy. Also, the bark is falling off of the trunk portion of my largest maple tree, but otherwise it seems to be healthy. (Pelican Rapids, Minn.)

A: Concerning your maple trees, I am sending you NDSU Extension Service publication F-1192, "Insect and Disease Management Guide for Woody Plants." It is an excellent, descriptive resource that should help you determine what is wrong with your trees. As for the bark, that is usually normal on older trees, especially when the weather conditions change so radically.

Q: I would like to know if there is a herbicide I could put on my strawberries. It is mostly quackgrass with a few other weeds. (Berlin, N.D.)

A: Yes. Poast is registered for quack in strawberries. Be sure to follow label directions.

Q: Could you send me some information on how to fertilize my apple tree? My tree is 40 to 50 years old and I believe it needs fertilizer of some kind. (Napoleon, N.D.)

A: Just because your apple tree is 50 years old doesn’t necessarily mean it needs fertilizer. If your tree is growing in a turf area that has received regular fertilization, the tree’s nutrient needs have likely been met. About the only thing apple or other fruit trees need in much of our region are the trace elements, iron, zinc, copper, etc., since they are "tied up" at the elevated pH of our soils.

Q: Do you have the instructions for sterilizing soil in a microwave? (E-mail reference, Minot, N.D.)

A: Take a pint of soil, place it in a ziplock bag, moisten ( not soak) and place in the microwave, with the bag open, for 2.5 to 3.0 minutes. That usually cooks any unwanted things in there pretty well. If it isn't too hot to handle, then do it again.

Q: I had a fellow ask me a question regarding a problem with his squash plants last summer. They would get squash anywhere from quarter to half dollar size and then the small squash would dry up. I had the same problem with my birdhouse gourds. I've searched all my books and information from the master gardener class and can't seem to find anything on it. Can you give me any help? (E-mail reference, Williston, N.D.)

A: This usually means that the pollination of the squash was either incomplete or non-existent. It happens when the stigma is ready to receive pollen and there is no male flower to supply the pollen, no insect to transfer it, or the weather is not conducive to pollination at the time the plant organs were ready.

Q: We had a gorgeous jade plant that was a picture of health since we got it in spring of 2000.

We went to Mexico in January and February, leaving the plant in our family room, not in very good light. It was watered three or four times while we were away, but on our return we noticed that the back side (darkest) had deteriorated badly with leaves and branches softening and falling.

We read your questions on jade plants and comparing symptoms, figure the plant possibly developed root rot. Is there any solution that could save this plant? (E-mail reference, Toronto, Canada)

A: From your description, it sounds like there is a chance you may be able to save the plant. I suggest the following action, as doing nothing at this time will not improve things: Repot, using a soil based mix along with about one part coarse sand or perlite. At that time, examine the root system and prune out anything that is obviously infected or rotted. Move it into the next nominal sized pot -- from a 6-inch pot to a 7- or 8-inch size, for example. It could be your jade got too warm while you were away. They like it cool–below 55 degrees F -- and on the dry side. If it was watered only three or four times in your two-month absence, that shouldn't have been enough to cause over-watering problems. I suspect that it could be due to the lower light that it was placed in. The good news is that your jade should recover and show signs of improvement as spring arrives. Summering it outdoors wouldn't be a bad idea either.

Q: I bought a couple of apricot trees a few years ago. They were supposed to be Sungold and Moongold. The trees now have grown to a good size and obviously are two different varieties. One tree (Sungold?) is very upright (almost columnar) and smaller and less vigorous. The other is more spreading and larger. I have had good blossoms from both trees but have noticed that their blossom times are different. One tree seems to have almost completely finished blooming as the other blossoms. Peak blossom seems to be about a week apart. I still get fruit set, but considerably more on the smaller tree. On the larger tree, I get some fruit set but it doesn't seem to survive to maturity and drops off. I see no sign of disease on either tree. I probably should mention this is a mixed orchard and there are apples, peaches, a Montmorency cherry, and even a Meador american persimmon nearby. There are plums about 100 feet away. I am located in Wisconsin on the border of zone 4 and 5. My orchard is at the top of a hill, so I figure it is more like zone 5. (E-mail reference, Wisc.)

A: I would suggest getting a couple more of each of the two cultivars for better pollen distribution between the trees. You are fortunate to be able to grow such a variety of fruit trees!

Q: I’m looking for information on starting trees from seed, mainly coniferous and deciduous for North Dakota. (E-mail reference, Cavalier, N.D.)

A: There are a couple of good books available "Seeds of Woody Plants in the U.S." USDA publication #450, and "Seeds - Ecology, Biography, and Evolution of Dormancy and Germination" Neither is casual reading, but they should be available at the local library, at least the USDA one. It is a fairly complete book and should answer your questions pretty completely.

Q: I am interested in information on diamond willow. Specifically I would like to know when the best time is to cut it to prevent it from breaking or cracking. (E-mail reference, Valley City, N.D.)

A: I have heard of pussy willow, sharp-leaf willow, laurel willow, white willow, blue fox willow, wooly willow, and many more, but never the diamond willow. Please, if you can, give me a botanical name. Salix what? This highlights the problem with using common names, as they may or may not have a relationship to the same plant generically. That said, the best time to prune about 90 percent of the deciduous trees in our area is now, before leaf-out, and that should include the "diamond willow" as well.

Q: I read your article on Confront on thistle. I have more thistle than grass in some areas, so I'd like to use it. Is it a restricted use pesticide? (E-mail reference, Fargo, N.D.)

A: Confront is not listed as a restricted use pesticide, although it is not available to the general public. It is sold as a "speciality herbicide" to lawn care operators. Trimec is obtainable, and about as effective. Thistles are a pain to control because of their high seed release, and the fact that they are so viable!

Q: I own 28 acres of land and want to restore prairie to parts that have been disrupted by construction. Slopes with a clay soil are common. Any ideas? Where could you recommend I get seed at a reasonable price? (E-mail reference, Yankton, S.D.)

A: I would suggest ordering your seed from as local a supplier as possible. From South Dakota, North Dakota, Nebraska or western Minnesota, if possible. Here is one you might want to contact:

Stock Seed Farms
28008 Mill Road
Murdock, NE 68407
Phone: 402-867-3771
Email: stockseed@alltel.net
www.stockseed.com 

They have a beautiful catalog of prairie plants that can be used for reclaiming or naturalizing.

Q: Can you tell me what kind of ant the enclosed specimen is? They mainly show up around my kitchen sink and really annoy me. They are so big in size compared to the ants I see normally. (Tyler, Minn.)

A: Since ant species are not my speciality, I took your sample to Phil Glogoza, NDSU extension entomologist. He immediately IDed it as a carpenter ant. As the name implies, this creature dwells somewhere within your housing structure. He suggests contacting a local pest control company and ask them to use Advance®, a registered carpenter ant bait that is effective in controlling them. It is safe around warm-blooded animals, but to be effective the bait needs to be placed where the ants are active.

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. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu