NEWS for North Dakotans
Agriculture Communication, North Dakota State
University
7 Morrill Hall, Fargo, ND 58105-5665
May 6, 1999
Hortiscope
Ron Smith, Extension Horticulturist
North Dakota State University
Q: Do you know of any plants that we could plant around our house to deter rodents from getting into our dirt-walled root cellar? (Milbank, S.D.)
A: Contact Kari Warberg at 1-800-583-2921 in New Town, N.D. She has a patented rodent repellent that works beautifully, made from essential oils of some herbal plants.
Q: What do you recommend for fighting weeds in my garden? (Lakota, N.D.)
A: Garden herbicides are most effective when they are applied to a cleanly cultivated area as a preplant or preemergence herbicide. Nothing controls all the weeds, so persistence is important. Try using clean mulch where necessary, in combination with these herbicides, and you'll at least have the satisfaction of knowing you're giving it your best shot.
Q: Could you tell me how and when to seed buffalograss and clue grama grass? (Wing, N.D.)
A: Wait until the temperature hangs near 75 F for a while and then sow the seed. The blue grama will come up first and eventually, so will some of the buffalograss. Maintain at a mowing height of 3 to 4 inches. Keep it moist until the grass is well established.
Q: Can you give me an address of where I can purchase some native wild grasses? (e-mail reference, Bismarck, N.D.)
A: You bet! Prairie Moon Nursery, Route 3, Box 163, Winona, MN 55987, 507-452-1362, e-mail: pmnrsy@luminet.net.
Q: Can you tell me what is causing mold to grow on my houseplants, and how to get rid of it? (Minot, N.D.)
A: There are two molds—a saprophyte that grows on moist soil, and a parasite that grows on living tissue. Control both by improving drainage, limiting water, and dusting with sulfur-based fungicides.
Something is out of balance—light, drainage, air circulation, moisture—to cause mold to form.
Q: I'm doing some research on growing and marketing Echinacea and would like to get some information on it. People around here have been digging it up out of the North Dakota prairie and selling it, but I am not sure where they are finding a market for it. Thank you for you help. (Bennett, Colo.)
A: Those that you see digging Echinacea in many cases, are doing so illegally. Price varies of course, with supply, but generally $12 to $15 per pound for quality dried root. We are trying to study national production on a commercial basis to prevent the destruction of both private and public lands across the prairies.
Q: Can you tell me what kind of fungus is growing on the enclosed sample of white lilac bush? I would also like to plant a new lilac there and I am wondering if it will have the same problems? (Cando, N.D.)
A: The new lilac will likely grow in the same location. Just make sure as much of the present shrub as possible is removed.
You have two maladies with the present lilac. One is the shelf-like structure on the wounded branch. What is happening is internal rot and what you are seeing are the results of this process. It is often found on old trees that have fallen or will soon fall, from internal decay.
The other disease is powdery mildew. This usually arrives on lilac leaves in late July or August. To keep under control, spray with sulfur, Bordeaux mixture or Benlate prior to the disease showing up.
Q: Can you tell me where I can send a soil sample to be tested from my garden? (e-mail)
A: Send the samples to: Waldron Hall, P.O. Box 5575, NDSU, Fargo, ND 58105.
Have the pH, organic matter content, N,P and K and soluble salts tested. Cost is about $20 per sample (they will send you a bill when the sample is done). Be sure to take a good representative sample.
Q: Can you tell me how to get rid of the suckers that keep appearing around my yard from a flowering crab that we removed? (Eureka, S.D., e-mail)
A: Treat the lawn area with a broadleaf herbicide that contains 2,4-D as if you were controlling weeds. It will likely take two to three years to completely get rid of the sprouting suckers, but it will be worth it, so hang in there!
Q: I want to spray my lilacs and phlox to prevent mildew this summer. My phlox, next to the building, are coming up. Is now the right time to spray them, or should I wait until later? Or is it too late already? (Fargo, N.D., e-mail)
A: You are a little early to be spraying fungicide for powdery mildew control. I suggest waiting until around Memorial Day weekend or about the June 1. Or, as a little more accurate gauge, when they start flowering.
Q: I am looking for some information on building a tennis court. (e-mail)
A: Tennis court grass (assuming that we are talking about North Dakota) should be a toughie, such as 50 percent perennial ryegrass and 50 percent quality Kentucky bluegrass. Mow it to about ¾ inches and keep it well watered, fertilized and otherwise well cared for between matches.
Don't be tempted to try bentgrass, the species used on putting greens. A special mower is needed, it is prone to disease under stress and it does not tolerate wear well.
Q: Have you heard of using copper barrier tape or pipe for slugs? (Fargo, N.D.)
A: Sorry, but I do not know anything about using the copper tape or pipe method you are talking about to control slugs. My attempts have all been old-fashioned: lime, egg shells and sunken beer dishes.
Q: My lawn is very poor and has a hard whitish substance on it every spring. I've been told our area is very alkaline and that it might help to put lime on it. Can you advise? Also, what is Fultz alkali grass? (e-mail)
A: Apply no lime. Fultz alkali grass is a species that is adapted to high-salt soils such as you are describing. There is very little one can do about such soils, except to live with them and plant adapted species.
Q: I am wondering why one of my evergreen trees is producing berries while the other is not? (Gettysburg, S.D.)
A: The junipers are mostly dioecious species—male and female sex organs on separate plants. The one with the berries was female and the one without was male.
Q: What is the best way to keep my raspberry patch weed free? Is it okay to use Round-Up on it? (Belcourt, N.D.)
A: Weed-free raspberries is a dream that will never come true. Reduced weed pressure can be realized through proper cultivation, mulches, and the proper use of herbicides like Roundup.
Here is what I would suggest:
1. Use shallow cultivation between rows to remove weeds.
2. Spot spray carefully any emerged weeds with Roundup
3. Seed a cover crop of creeping red fescue or Covar hard fescue at a rate of 80 to 100 pounds per acre (for quicker establishment, you may want to mix in come perennial ryegrass).
4. Fertilize at a rate of 60 to 80 pounds of nitrogen (N) per acre to keep the grass healthy, and mow it three or four times a year.
5. You may want to mix in some white clover (Trifolium repens) to supply some of the N.
6. Whatever you do, maintain about 3- to 4-foot strip of weed-free soil within the raspberry row. This can be achieved with organic mulches once the emerged weeds are under control.
7. Herbicides that are registered for weed control in raspberries are Casoron 4G (grassy weeds and some broadleaf pests like Canada thistle), Poast, Princep and Suflan. Roundup of course can be used any time active growth of weeds is taking place, but spray should not be allowed to drift into raspberry foliage.
Always be sure to follow label directions, as inappropriate timing of application can wipe out a crop.
Q: I would like some information on hibiscus plants. When I received my plant it had three in one pot, and I am wondering when I should repot them, and if I should split them up? (Parshall, N.D.)
A: The three plants in one pot were for maximum visual impact for retail sales purposes, not for the health of the plants.
Repot separately, cut back hard and give them a shot of Miracle-Gro. When our weather finally settles down, summer them outdoors.
Q: Can you tell me what is wrong with my Christmas Cactus? I don't know if it needs water, or if it had too much water, or what. (Detroit Lakes, Minn.)
A: You are most likely over-watering—or it is in a non-draining container.
It may be a good time to repot now in a free-draining container. Christmas cacti are pretty tough! It would take more than the water you use to kill this plant. Allow it to dry between waterings.
Q: I have been nurturing India rope hoyas for several years and now they have developed mealy bugs. I have tried spraying them with Orthene Systemic Insect Control and with Volck Oil Spray, but the bugs still come back. Is there some other way that I can get rid of these bugs? (Heindal, N.D.)
A: It sounds like you've made every reasonable attempt to control the mealy bug pest! The only suggestion I can come up with is to try and locate a fumigant card that gives off vapors that will eliminate them. Place the plant or plants in question in a sealed plastic bag or container, for a 24-hour period, and that should do it.
Another possible option is to dip the foliar part of the plant in insecticidal soap solution. Being soft-bodied, this relatively harmless insecticide should be quite effective on these persistent pests.
Q: Can fireblight affect green ash? Is the fungus airborne or does it need direct contact? Can I plant a new green ash 10 feet from where the old one has been removed? Does the fungus live in the soil? (Faulkton, S.D.)
A: First of all, fireblight is not a fungal disease, but a bacteria infection. It infects, potentially, any member of the Roseate family. It is airborne and is most troublesome on this plant material after a hail storm followed by warm, humid weather. The denser the population of vulnerable hosts, the easier the disease will spread.
Prune the infected branches ASAP before bud-break. If this arrives after the buds have already opened, place a bag over the infected branch, tie it and cut it off cleanly. Do not use any pruning paint.
Spraying should begin at blossom time, and continue for three more applications, spaced five days apart.
Q: Is there anything I can do to get my flowering crab to stop producing so many berries? (Battle Lake, N.D., e-mail)
A: You can try using the insecticide Sevin, spraying at three-quarter blossom, and again a week later. Do so early in the morning or later in the evening, when the honeybees are not active. This may reduce the apple population by about 75 percent, depending on the cultivar or variety it happens to be.
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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.
Source: Ron Smith (701) 231-8161 ronsmith@ndsuext.nodak.edu
Editor: Dean Hulse (701) 231-6136