Lawns, particularly those that contain a high proportion of annual bluegrass (Poa annua)
patches of grass become yellow and die, often merging to form large areas
in damp weather, a white fungal growth appears, causing the grass blades to stick together.
it is most prevalent in late winter and early spring, especially on areas of grass that have been waled on while snow covered
principally the fungus Fusarium nivale, which is encouraged by poor aeration and the overuse of nitrogen fertilizers
Regularly aerate and scarify the lawn. Use winter-hardy grass species. Avoid using high-nitrogen fertilizers in late summer to early fall and rake thoroughly after mowing to prevent building up a water-holding mat. Cut grass short in late fall.