The snowstorms of winter create ideal conditions for snow molds to form on your lawn. Pink and Grey Snow Molds  sometimes appear on grass as snow cover melts looking like cooked spinach. In late winter-early spring, dead and matted grass blades in rough circular patches about 3 to 12 inches in diameter are most likely snow mold. The two different diseases get their names from the pink-salmon color or white-gray color they display. Gray snow mold rarely does damage to the turf while pink snow mold can invade the crowns and roots of grass plants causing turf grass injury. Both types of snow mold can be found in the same areas on the grass. Temperatures just above freezing and moist conditions are ideal for snow mold development. This usually occurs from snow cover, but can also happen if leaves are left on the grass from the prior fall. If you have had a history of snow molds over the years, it may return each winter when early, deep snow cover prevents the ground from freezing. Snow mold fungi remain alive on your grass during the warm months when other summer diseases fungi are most active. As the cool, wet weather approaches, these fungi begin to grow. The cold, dry air of winter helps to prevent growth, but leaves or snow cover on the grass promotes growth, since moisture is kept near the grass blades. As the grass starts to dry out, these diseases generally go away. 

Grey Snow Mold

How do you prevent this from happening to your lawn? Following a sound Jonathan Green lawn maintenance program is the best way to prevent snow mold diseases. From late summer to late fall, be sure to continue to mow your lawn until it stops growing. When you get to your last mowing cut the lawn shorter than usual. This prevents lush growth from being available for snow molds to develop. Early fall fertilizing with Green-Up lawn fertilizer should occur while the grass is still green, not after it goes into its winter dormancy. In mid-to-late fall our Winter Survival fall fertilizer is a good choice to use. Fungicide treatments are not usually recommended. A preventative fungicide treatment with our Lawn Fungus Control in October or November may be helpful. Be sure to clear the last bits of fall leaves from your lawn before the first snowfall occurs. Avoid piling the snow from your driveway and sidewalk on the lawn. In the spring, rake away dead matted foliage from damaged areas to allow new growth to begin after the grass had dried out. Aeration promotes new growth of the existing grass where snow mold appeared. Reduce thatch so that it is no more than one inch in depth. Be sure to correct any drainage problems if water is sitting in puddles since this promotes snow mold. As always, use a Jonathan Green high quality grass seed mixtures that include Kentucky bluegrass and fescues, which are more resistant to snow mold disease. Seeding with Black Beauty Ultra grass seed and New Seeding lawn fertilizer helps to fill in bare spots. 

I hope you are able to enjoy your nice spring green lawn instead of worrying about fungus on your lawn. Have a great spring!