Now that the snow has melted from north facing areas, we are seeing gray snow mold. These matted areas occur when your grass is covered with snow for prolonged periods of time and temperatures are slightly below freezing.
The freeze and thaw that takes place under the snow is what causes this disease to form in the spring. The damage caused by snow molds is seldom serious. Now that the snow is gone, the best thing to do is gently rake the matted turf allowing it to dry. Gray snow mold activity stops when the temperature exceeds 45° F or the surface dries. In a few weeks, your grass will be green and healthy.