University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Lawns May Look Ragged as Snows Melt

February 22, 2001

Lawns have been under the cover of snow since early December. As this snow melts away, many lawn areas are likely to look quite ragged. In most cases, the appearance will improve dramatically as conditions warm and lawn growth resumes later in spring.

Damage from the fungal disease snow mold is one likely problem. Snow mold may be highly visible as matted crusty looking areas. As conditions dry out, snow mold will gradually disappear but infected areas may remain in the form of weak or even dead turf. Conditions favorable for snow mold include excessive use of nitrogen fertilizer in early to mid fall, excessive thatch, shade, poor drainage, and debris (such as leaves or straw) on the lawn.

To help avoid snow mold next season, follow sound fertilization programs, using fertilizers containing slow-release or controlled-release nitrogen. Adequate levels of phosphorus (P) and potassium (K) should be available in the soil. Manage thatch by core aerifying or vertical mowing (dethatching). Improve air circulation by pruning or removing dense vegetation bordering problem lawn areas. Mow lawns until completely dormant in fall.

Another problem is voles, which make runways under the snow in lawns as they feed on grass blades and roots and are protected from predators. Voles, or meadow mice, are about 4 to 6 inches long and brownish-gray in color. Damage is frequently mistaken as mole damage, but moles are not active during winter and actually tunnel below the soil surface. Vole damage appears as runways or winding trails of damaged grass.

Lawns usually fill-in as conditions warm in spring. Severe damage may require some overseeding, however. Help prevent damage from occurring by continuing to mow lawns until grass is completely dormant in fall. Mow lawns at a final height of about two inches. Also clean up any excessive vegetation near lawns, as this provides cover for voles.


Click here for the full article index