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

May 27, 1999

Ron Smith, Extension Horticulturist
North Dakota State University

Q: What can be done to create grass regrowth in the white spots of a lawn caused by female dog urine? (e-mail reference)

A: There is only one thing to do—leach the salts with excessive water. This would involve taking a hose with a nozzle and soaking the area two or three times to get the salts removed from the root zone.

Q: Will Preen help control creeping jenny in my yard and flower beds? (Glenfield, N.D., e-mail)

A: I wish Preen would control creeping jenny. Unfortunately, that simply is not the case, and we are forced to pull out the heavy artillery to bring it under control—a Trimec product to control just the weed or Roundup to wipe out everything. Or, you can learn to live with the creeping jenny where it is the dominant plant in your yard. It makes an excellent groundcover where turfgrass will not grow. The decision is yours!

Q: I have two whiskey barrel planters that are full of ants. I have tried using traps, but it is not solving the problem. Would taking the soil out and replacing it help or would spraying the soil help, or do I need to get new planters? (Williston, N.D., e-mail)

A: Ants are there most likely because there is a source of food for them—most likely aphids that are feeding on the roots or stems of your plants, and the ants are "tending" them to collect the aphids' honeydew. If you apply the insecticide Sevin or diazinon, you should get control. Follow the directions on the label. You shouldn't need to replace those expensive whiskey barrels!

Q: Three questions: One, how can you divide or increase clematis vines? Two, I have 40 to 50 crocus bulbs that are 3 years old. They grow beautifully, but only four or five blossom. Why, and what can I do to make them blossom? And three, I have an ornamental almond bush that has blossomed for three years and is spreading. Can I cut back some of the stems to control its size without harming it? (Robinson, N.D.)

A: 1. Clematis can be propagated just about any way you want—by seed, cuttings or root division. The easiest way is by stem cuttings on spring wood or later in the spring after the wood has matured. Leaf-bud cuttings taken in summer that can be kept under mist also root easily.

2. You may have them planted too deep, or they may need fertilization.

3. Yes, you can prune the almond to a more desirable shape with no harm done.

Q: Can you tell me why the leaves from my coffee tree keep falling off? (Bison, S.D.)

A: Coffee plants need a lot of bright, indirect light, an even moisture supply—no drying between watering—and to be kept away from drafts. Any one or all of those care factors will cause leaf drop.

Q: My spider plant and peace lily leaf edges are turning brown. What is causing this and how can I make it stop? (Marion, S.D.)

A: The brown tips or edges are usually the result of salts in the water—chloride, fluoride, sodium, etc. And yes, both the peace lily and spider plant are sensitive to these salts. Try watering with distilled water and see if it helps. I have the same problem on my plants as well.

Q: A weed that grows in my yard seems to be spreading more every year. I've tried Ortho Weed-B-Gone, but it doesn't touch it. (Eureka, S.D.)

A: You have one of the toughest weeds to eliminate in the lawn—violets. They will need repeat applications of Trimec to take them out. This can be obtained from any garden center or garden supply store.

Q: Ugly grass is taking over my lawn. (Groton, S.D.)

A: Your sample was nimblewill, a perennial, creeping grass that resembles bentgrass but turns brown in winter. There is no selective herbicide for it, so your only option is to use Roundup to kill it, and then seed with a desirable grass like common Kentucky bluegrass.

Q: Can you tell me what type of prairie grass is native to this area? I would like to plant approximately one acre back into native grasses. (Grand Forks, N.D., e-mail)

A: The eastern region of the state is generally known as the tallgrass prairie. Being unfamiliar with your specific site, it may be a different ecosystem, but I would think a tallgrass mixture would work out OK for you.

A mixture that would include big bluestem, Canada wildrye, switchgrass, and Indian grass, along with the usual wildflowers of purple coneflower, the various black and brown-eyed Susans, New England asters, dame's rocket and others should give you a fairly attractive stand.

Be warned: your ambition will cost you many dollars, but it will be beautiful once completed.

Q: My iris leaves have little round spots on them, with some of them so bad they are turning brown and curling up. I have applied malathion 50-percent spray twice since May 1, and it isn't any better. Even seems worse. What is it, and what can I do? (Aberdeen, S.D., e-mail)

A: It sounds like your irises are suffering from a common malady known as Didymellina leaf spot. If we are not too late, try controlling it with Zineb, also known as Dithane. These materials should be readily available in any garden store or nursery. Hope you can catch this in time!

Q: Our neighborhood is being overrun with nightcrawlers. What can be done to get rid of them? (Minot, N.D.)

A: Nightcrawlers are troublesome at this time of year, especially with all the rain this spring.

A couple of methods can be employed:

1. If you want to wipe them out, applications of Sevin or diazinon, following directions for grub control, would do the trick. Then simply use a ballast roller to flatten out the lumps.
2. If you want to keep the worms around for soil aeration but don't want the pilings that go along with them, simply knock them down with a power rake before Memorial Day.

Q: I have some dahlia bulbs that I started in pots to give them a head start, and when they were an inch high I brought them upstairs to give them some light. I was planning to put them outside for short periods of time to harden them up, but before I had a chance the weather turned windy, then rainy. Now they are 2 to 3 inches high. Can I still harden them or can they be trimmed? I also would like to know if I can safely use Preen around my rose bushes and hydrangeas to get rid of the creeping jenny or dharlie that is in them? (Glenfield, N.D., e-mail)

A: Yes, you can still harden them off and even prune them back if you wish. The wind will be the biggest enemy of these (and most plants in North Dakota!), so you may want to stake them or find a protected spot for them in the landscape—if such a place exists.

Yes, Preen can be used safely around roses. Creeping jenny is a tough weed to bring under control. If you have a pure stand of it, use Roundup to kill it off. It may take repeat applications to get rid of it. Where it is mixed with grass, you may have to use a formulation known as Trimec to bring it under control. Fall—between mid-August and mid-September—is the best time to control this and other broadleaf perennial weeds.

Q: Can you tell me what I should do with my rhubarb that is already going to seed? Can I pick winter onions now? How do you know when they are ready to pick? (Williston, N.D., e-mail)

A: Rhubarb should not be allowed to flower and set seed. Cut the stalk off. Winter onions should be harvested in spring—now—so enjoy!

###

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: ElRoy Haadem (701) 221-6865

Editor: Gary Moran (701) 231-7865