Gray Snow Mold
This disease usually first appears when snow thaws in the spring, commonly found in lawn areas of greatest snow accumulation. The most noticeable symptoms include bleached, white crusted areas of grass, leaving the blades dead, bleached and matted together. These bleached areas can range in size from several inches to several feet in diameter.
The chief diagnostic feature of gray snow mold is grass stained with hard, dark-brown to light-brown pinhead-sized fungus bodies. These are embedded in the leaves and crowns of infected grass plants as patches of disease, threatening the health of your lawn. In most cases the fungus does not kill the grass or the roots, but it causes death to the grass blades and weakens the plant structure making your lawn susceptible to problems later in the year.
The fungus will survive in the thatch, clippings and crown area of the turf until the following winter. Under the cover of snow, these bodies germinate, growing a fungus that induces infection. Gray Snow Mold seldom occurs, except under snow cover when the soil is not frozen. Of course, this is typical in areas where snow falls on unfrozen soil and melts gradually, trickling water down the turf, feeding diseases and fungi that will litter the blades of your grass.