NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
July 15, 1999
Ron Smith, Extension Horticulturist
North Dakota State University
Q: Can you identify the enclosed plant for me? It blooms for several months in the fall and then it turns to red berries. (Breckenridge, Minn.)
A: The plant is deadly nightshade--lovely to look at and to behold, but take one taste, and you'll end up cold. Heed the advice!
Q: I fertilized my strawberries right away this spring, but when I should fertilize again? (New England, N.D.)
A: It is a good idea to give your berry crops a couple of fertilizations per year--in the spring before fruit set and again after harvest. That way, the crops are at their optimum for setting and developing fruit and for building tissue and carbohydrates for next year.
Q: We had the lawn sprayed last spring, but it did not kill this one weed. How do I get rid of it? (Rugby, N.D.)
A: The weed is Glechoma, also known as ground ivy. It has a nasty root system and so the best lawn spray to use is Trimec, the strongest herbicide on the market. You should be able to find it all most home and garden centers. Remember to follow the label instructions.
Q: In a recent response to a gardener you thought the snowball bush was a hydrangea. I believe the writer was referring to the snowball shrub. (Valley City, N.D.)
A: Of course it is! It is Viburnum opulus. The Roseum cultivar produces white sterile flowers. I should have know better, and shame on the garden catalog for not using botanical names!
Q: How can I get rid of chickweed? (Bowdle, S.D.)
A: An annual, chickweed is a prolific seed producer, and the best way to control it is via a continuation of attacks:
- Continuous weeding will eventually reduce the soil seedbank population, but you'd probably wear out in the meantime.
- There are a number of herbicides that will kill the weed on contact--2,4-D and Weedone are two examples.
- Use a pre-emergent herbicide early next spring--such as Pendimethalin--to keep the seeds from germinating.
- You can try one last tactic, which is almost guaranteed to spell its demise--cultivating it as a crop!
Q: My rose has problems. (Washburn, N.D.)
A: Your rose has an advanced stage of a fungal disease known as black spot. You need to cut back all diseased wood and dispose of it. You also should avoid all overhead watering and splashing when watering. Follow good sanitation and clean up all fallen leaves. Spray with benomyl, chlorothalonil or mancozeb as new leaves appear in the spring and repeated every 10 days all season long.
Q: Can you tell me how keep a rose tree through the winter? (Langdon, N.D.)
A: Rose trees need to be buried in our region to get through the winters. Once it is dormant, dig a trench and lay the tree in it, covering with soil, straw, or leaves or some of each. When spring arrives, dig it up and replant.
Q: Can you tell me the proper way to take care of my Swedish ivy? (Valley City, N.D.)
A: Cut it back hard, repot and place it in a sunny location. Give it a shot of fertilizer with the first watering. After that, watch that you don't get excess water on the foliage and that you throw away any drainage water from the bottom of the pot.
Q: I am trying to start a spraying program for blight on my tomatoes and I was hoping you could make some suggestions. (Maple Plain, Minn.)
A: You are smart to get a head start on these diseases. The NDSU Extension Service publication titled "Disease Control in Home-Grown Tomatoes" (PP-659) highlights what you need to do. Spray with chlorothalonil, mancozeb or maneb, and try to keep the foliage dry when watering.
Q: Can you tell me how to produce a fall crop of kohlrabi? (Berkley, Mich.)
A: You can grow a fall crop of kohlrabi if you set the plants out in mid- to late-August. As with other members of the cabbage family, it can tolerate the initial light frosts of fall, and you can throw a light cover over them when a heavier frost is expected.
Q: Can you tell me how to control white flies on my hibiscus? I also would like to know if you could give me some information on the best care for them. (Moorhead, Minn.)
A: I would suggest that you look for an aerosol or pump spray labeled for use of white flies at a local hardware store. Be sure to follow the directions, but it's best to spray under the leaves and on the stem to make sure you cover the areas where the white flies are more common.
To keep your plant alive (some live 20 years or more indoors!), repot it in a larger-sized pot each spring. Once the largest convenient sized pot is reached, topdress it instead each year. This calls for scraping off the top 1 or 2 inches of soil (be careful not to expose major roots) and then refill the pot with fresh soil up to the original level. Add a slow release fertilizer at the manufacturer's recommended rate. They enjoy average home temperatures, but cooler winter temperatures--about 55 F. In the meantime, allow it to spend the summer outdoors.
Q: How long do these cultivar ash trees, such as Patmore, typically live? What should I do with my Easter hydrangea? I have read that the Easter chrysanthemums tends to be an annual, or at least not hardy. Is this so? What does one do with an amaryllis? Are yarrow and beebalm easy plants to propagate? (e-mail)
A: I have no stats on the Patmore ash for longevity, but it would be reasonable to assume that they could live most of a century as their "uncultivated" kin do.
Summer both the Easter hydrangea and chrysanthemum outdoors. Throw the mum away when it is killed off by frost. The hydrangea may survive our winters if it is the right cultivar, so leave it outdoors and see what happens.
With an amaryllis, one attempts to rebloom it by planting it outdoors for the summer, then bringing it inside and allowing it to dry down. Around Halloween, begin watering again and see if you get a flower again. If not, try the whole cycle again, or simply dump it and buy another one!
Propagate the roots or rhizomes of yarrow and beebalm.
Q: I have been trying to grow any kind of maple tree without any success at all. Is there a certain type of soil required, or is it our climate? I have tried planting in the spring and in the fall, but they always die out.
When can I apply Roundup or weed killer to my tulip bed? Do I have to wait until all the tulips are dried up? (e-mail)
A: I would guess that the Amur or Tartarin maples would be the best choice. Or, if you are really desperate, you could try the boxelder maple--that grows just about anywhere! If none of these three have been tried, I would suggest giving them a shot. I suspect that you have tried silver maples in the past. They are very sensitive to high soil pH that exists in your area--and most others across the state.
Yes, your tulips need to completely die back before using any Roundup in the area. They should be close to that stage by now, with all the warm weather we've had.
###
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