Gray Snow Mold (Typhula Blight) Fungicides

Gray snow mold, or Typhula blight, develops beneath long-lasting snow cover and is most damaging where snow falls on unfrozen, lush turf.

What to Look For

After snowmelt, circular straw-colored patches may be covered with gray-white mycelium. Small dark or reddish-brown sclerotia can be found on leaves and crowns. Leaves may be matted, but crowns often survive and recover.

Why It Develops

Extended snow cover, unfrozen soil, heavy late-fall nitrogen, tall matted turf, and piles of plowed snow increase risk.

Reduce Disease Pressure

• Avoid excessive late-fall nitrogen and finish mowing before snow cover.
• Disperse snow piles and improve drainage in chronic areas.
• Gently rake matted turf after snowmelt to improve drying.
• Use adapted, tolerant turf species where winter disease is chronic.

What University Research and Extension Guidance Says

University guidance emphasizes a final preventive application shortly before dependable snow cover. Spring fungicide applications do not repair damage after snowmelt. Multi-active programs are often recommended where snow cover is prolonged or where both gray and pink snow molds occur.

Choosing and Using a Fungicide

Use the products below as a starting point, then match the active ingredient, FRAC group, turf species, use site, timing, rate, interval, and watering directions to the current product label. Preventive or very early applications are usually more reliable than rescue treatments after extensive injury. Rotate effective FRAC groups and combine fungicides with the cultural changes above.

Research and label note: University research may identify useful activity even when a current product label does not name this disease. That is research evidence, not a label direction. Apply a product only where the turf or application site and use pattern are permitted, and follow the complete label and applicable state requirements.

University sources: Penn State Extension: Gray Snow Mold; University of Kentucky: Chemical Control of Turfgrass Diseases 2024.