What Is Snow Mould and How Can You Prevent It on Your Turf?

White (Grey) Snow Mould (Typhula incarnata) is a strictly a cold weather turf disease, it appears as a fluffy white/grey or pink residue caused by the Typhula fungi.

The fungi spend the warmer months as sclerotia embedded in infected grass blades and in the turf canopy. Sclerotia are very small black to orange structures that can survive hot, dry conditions. Heavy moisture and near-freezing temperatures trigger germination of sclerotia and infection of grass plants.

A situation that often produces these key conditions is a deep snow or heavy mulch covering wet turfgrass before the ground has frozen. It invariably seems to follow a retreating snow line. White snow mould activity will be slowed when the snow cover is gone due to winter thaws, but the activity will resume every time it snows, regardless of whether it is a light flurry or heavier snow. Injury to the turf is aggravated when the snow is compacted by walking, etc.