School IPM Best Practices

Pink Snow Mold, Microdochium nivale and Gray Snow Mold, Typhula spp.

Snow mold

Photo by William M. Brown Jr., Bugwood.org.

IPM Steps to Reduce Snow Mold

1. Sample for Pest

Confirm the presence of snow mold before you treat.

Where to find it while inspecting: Damage shows up on grass after snow melt while grass is still moist. Snow mold fungi are present but inactive during the warm months. Snow mold becomes active under the right combination of conditions, so you can predict and watch for it. Signs of gray snow mold: look for white mycelium (tiny threadlike structure between grass blades) before they dry up. Infected turf will have tiny brown to black spots (fungal sclerotia). Pink snow mold: white mycelium fades to pink as they dry. Pink snow mold does not produce sclerotia.

2. Proper ID

Is it snow mold?

Size and Appearance: Snow molds cause round damage marks in damp turf of 3–12" and can coalesce under severe conditions.

3. Learn the Pest Biology

What is the life cycle of snow mold?

Life Cycle: Snow mold fungi survive in thatch and grow in cool, wet weather. It can thrive in lush grass on ground that is not yet frozen and is covered with snow and will show up as turf damage when snow melts (either springtime melt or fluctuations in snow and warm during winter).

Preferred Food Sources: Fungal diseases obtain nutrients by the breakdown of organic matter.

Preferred Habitat: Most often survives in thicker, higher turf going into the winter where it is protected from drying out. Often found in turf that is actively growing due to fall fertilization.

4. Determine Threshold

How much snow mold is too much?

Threshold: Snow mold is hard to predict unless there is a consistent problem. Repeated damage to turf may call for action, but weather conditions are the major contributor. Heat and dry air are natural enemies of snow mold.

5. Choose Tactics

Creating a healthy soil condition and understanding turfgrass’s needs is the first step in reducing turf pests. What can I do to treat, reduce, or prevent snow mold?

Best Management Practices: Lowering the mowing height at the end of the season, and reducing thatch before winter reduces snow mold problems. Rake away dead and matted turf material in fall and spring. Apply fertilizer more than 6 wks before normal dormancy period of your turf. Overseed heavily damaged areas in Spring.

Treatment Methods: Preventive fungicide treatments are an option for extreme conditions with repeated damage but are rarely needed outside golf course turf management.

6. Evaluate

Was the tactic successful? Record the date pests were first noted, and the tactic you used, and its success. Use one of our RECORD KEEPING tools

For More Information:

Penn State Plant Science: Pink Snow Mold and Fusarium Patch


When a pesticide application is necessary, all necessary and required precautions are taken to minimize risk to people and the environment and to minimize risk of pesticide resistance or pest resurgence. Pesticide use in your school may be prohibited or regulated by local policies or state and federal regulations. Risk reduction methods can include, but are not limited to, spot-treatment, the use of gel or paste bait formulations placed in inaccessible locations, injection into a crack or crevice, and other methods that reduce potential exposure.