Pathogen

Microdochium nivale

Host

Annual Bluegrass, Kentucky Bluegrass, Rough Bluegrass, Colonial Bentgrass, Velvet Bentgrass, Creeping Bentgrass, Perennial Ryegrass, Fine Fescue, Tall Fescue

Environmental Requirements

32-45 F, high moisture, under snow cover or cold rain, lush foliar growth

Stand Symptoms

Without snow cover: circular reddish-brown patches, with snow cover: circular bleached and matted patches

Plant Symptoms

Plants are matted and may appear pink from spores

Fungal Signs

Immediately following snow melt, pink mycelium at margins of the patch

Environmental Modification

Avoid lush growth going into winter, mow grass until growth has stopped

Plant Resistance

Kentucky Bluegrass and Fine Fescues are the least susceptible