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

March 19, 1998

[Editors: When using this story, please include byline.]

Welcome to Spring! What to Expect in Your Yard as the Snow Melts

Ronald C. Smith
NDSU Extension Horticulturist and Turfgrass Specialist

To this point, Mother Nature has been kind to us. We entered the winter gradually, with plenty of moisture in the soil. Snow fell gently through most of the winter. We had a February thaw that provided plenty of moisture, then a typical return of "March madness" as far as the weather goes. Western North Dakota residents have been concerned about the buds swelling on many of their woody plants, and just about everyone has been concerned about what to expect with their lawns.

As to the lawn, expect to see more snow mold than normal this year. Snow mold is characterized by the telltale black slimy appearance of the turf. The disease tends to form in circular patterns and almost always follows a winter where snow lingers in a particular area accompanied with excessive water in the soil. Whenever snow falls on unfrozen turf and the turf remains covered for an extended period, conditions are set for several types of snow mold to develop: caprinus snow mold, pythium snow blight, snow scald and typhula blight. Another fungus, sometimes called pink snow mold (fusarium patch), will show up in areas of high moisture and poor drainage, even in the absence of snow.

To control snow molds, do these things:

  1. Manage large drifts of snow covering turf areas. Spread the snow out or remove it as best as possible to allow for faster drying.
  2. Rake affected areas with a leaf rake once the frost is out of the soil, to clean up area and facilitate drying.
  3. Fertilize area lightly to stimulate new growth; if none occurs, reseed.
  4. Control poor drainage and thatch accumulation with annual turf aeration.
  5. Avoid high seeding rates in any renovation or lawn establishment program. This perpetuates immaturity and encourages the development of pathogens like the snow molds.
  6. Avoid high fertilization rates in the fall with highly soluble forms of nitrogen. Use sources that are high in WIN (Water Insoluble Nitrogen) to prevent overstimulation of leaf growth.
  7. Keep the grass mowed going into the late fall. If there are areas that have a snow mold history, make the final mowing of those areas about one inch shorter.

Following good cultural practices will diminish the occurrence of these early season diseases.

Crabgrass, a warm-season grassy weed, will also be favored this year because of the mild winter conditions and high soil moisture. There is a new fungicide available for homeowners, known as Dimension, which provides a broad window of protection—up to 160 days, even if the crabgrass has already begun to emerge. The product is available either in conjunction with fertilizers (weed and feed combos) or as a stand-alone application. It also controls some 20 other problem weeds normally found in turf. For more information on lawn weed control, contact any county office of the NDSU Extension Service and request a copy of the publication H-1009, "Weed Control in North Dakota Lawns."

Flower buds are the first to come out of winter dormancy and are therefore the most prone to cold damage. With the warm weather teasing that took place in February, expect to experience poor fruit set on the blooms that were either partially or fully open. Any leaf buds that had begun expanding would also be vulnerable to the returning low temperatures experienced in early March. But not to worry—not all the buds emerged, so even if some were damaged, the others that did not open will leaf out later in the spring.

As for the leaves remaining from last fall, they will complete their abscission layer and drop off as spring comes on.

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Source: Ronald C. Smith (701) 231-8161

Editor: Barry Brissman (701) 231-7866