The weather has been so wet and cold this spring (if we can call it that, really), that we are suspecting that Red Thread Disease will be a greater issue for homeowners in Bergen & Passaic Counties in New Jersey and Orange & Rockland Counties in New York. What Is Red Thread Disease? Red thread disease is a fungus that affects turfgrass when there are moderate daytime temperatures, cooler nights and high moisture. The fungi live in the soil and thatch layer and feed off the gr