NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665

February 3, 2000

Hortiscope

Ron Smith, Extension Horticulturist
North Dakota State University

Q: I had two smoke trees in my yard that were broke off, one to the ground and the other is about 6 inches tall. All kind of sprouts came up. Will they amount to anything or should I start with new trees?

We planted 13 acres into grass and white clover. Last summer and fall was good growing weather for dandelions. Is there any kind of spray that will kill only the dandelions? (Pelican Rapids, Minn.)

A: Your smoke "trees" are Cotinus coggygria, a plant that is more of a shrub rather than a tree--getting about 10 to 15 feet tall and as wide. Cotinus coggygria is definitely hardy in zone 5 but questionable in zone 4. You must have grown it in a protected microclimate. If it was up to me, I'd let the sprouts take off and see what develops. It will be interesting at least and possibly attractive and functional.

To simply take out the dandelions and not kill the clover, I suggest using 2,4-D. It may toast the clover somewhat, but in my experience it has always come back. Be sure to follow label directions.

Q: We have a miniature rose plant that we brought in last fall. Every other week we have to spray the plant because white bugs get all over it. They make webs on the leaves and stems. There are also brown spots on the leaves. Whenever we spray, it sets the plant back. I used Schultz insect spray for houseplants and Eight insect control for house and garden plants. I also planted garlic in the soil and washed it many times. The bugs look like spider mites, and the directions on back of the ready-to-use spray said it was for spider mites. What do you suggest we do? (Fingal, N.D.)

A: Miniature roses are one of the biggest houseplant challenges a person can have. They don't respond well to the low light, dry, drafty conditions and cold water--all typical conditions during the winter. When I lived in Ohio, I was a big fan of miniature roses until I tried to get them through an entire year. I finally gave up!

If you wish to continue the battle, I would suggest the following strategy:

  1. Get some insecticidal soap and dip the entire top of the plant in the solution.
  2. Take the plant out of the pot and clean the container completely in hot, soapy water. Rinse, and then repot in fresh, high-quality potting soil.
  3. Place the rose under fluorescent lamps (or other plant lights) about 1 foot from the top of the plant.
  4. Always water with distilled, room-temperature water.
  5. Keep the rose away from other houseplants so reinfestation cannot occur.
  6. If this doesn't work, then give up!

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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