Snow Mold
Microdochium nivale (pink snow mold), Typhula incarnata, T. ishikariensis (gray snow mold)
Overview
Fungal diseases of turfgrass and winter cereals that develop under snow cover or during cool, wet conditions. Appears as circular patches of matted, discolored grass when snow melts.
Symptoms
Circular patches of matted, bleached, or pinkish-gray grass visible after snow melt. White to pink mycelium on grass blades. Gray snow mold produces small, dark sclerotia. Grass may recover from pink snow mold but gray snow mold kills crowns.
Environmental Conditions
Cool
Prevention
Avoid late-fall nitrogen fertilization. Mow grass short before winter. Reduce thatch. Improve drainage. Avoid piling snow on turf. Use resistant grass varieties.
Management
Rake matted grass to promote drying and recovery. Apply fungicides in late fall before snow cover in severe areas. Improve air circulation. Overseed damaged areas in spring.