What is Snow Mold and How It Can Be Prevented

Snow mold is a cold-weather fungus that affects cool-season grasses. Learn what is snow mold and what you can do about fixing and preventing it.

What Is Snow Mold?
Most indicators of spring are the good ones, like bloom, warmer temps, green grass, and buds. But gray-colored circles on your grass? Not hardly. Snow mold is due to cold-weather fungi that typically affects cool-season grasses. Signs of an issue aren’t seen until the spring when the snow melts.

Signs of Snow Mold
Symptoms of both gray and pink snow mold are typically most noticeable in the spring when the snow starts to melt. As the snow melts, circular patches varying in size from a couple of inches to several feet appear in your lawn.

The grass in these patches is generally crusty and matted down. The spots will have a white-grayish look if they are due to gray snow mold or a pink-whitish look when due to pink snow mold. Pink snow mold can be more hazardous than gray snow mold since it kills the roots and crown of grass plants. Gray snow only affect grass blades.

How to Treat Snow Mold
The key to fighting snow mold is prevention. There aren’t any treatments that work on snow mold when the snow melts in the spring. If you have repeated problems with snow mold in the springtime, you can use a preventative application of fungicide in fall before the first heavy snowfall.

If you don't use a preventative fungicide in fall and you see snow mold damage in your yard, the first thing you should do is gently rake the affected spots to loosen the matted grass. This will aid the lawn in drying and giving unaffected grass space to grow. You can also reach out to a tree specialist to inspect your outdoor area.

Once you’ve got your lawn back in order, it’s critical to maintain it in a way that deters snow mold in the winter. Keep mowing your grass until the growth has stopped altogether. Tall canopies make snow mold worse. Lastly, you should dethatch your lawn around late fall to eliminate as much build-up as possible before the snow begins.​