Snow mold is a fungal disease that can rear its ugly head when snow melts in early spring. It’s a common occurrence on lawn turf in years when early winter snows cover an unfrozen ground or when ground conditions are unseasonably wet. Since homeowners in many SavATree service areas just experienced a couple of very heavy late-winter snowfalls (and right after days of unseasonably balmy temperatures), the conditions are perfect for the growth of snow mold.
There are two varieties of snow mold: gray snow mold and pink snow mold. For both varieties, symptoms first appear in the lawn as circular, straw colored patches, which continue to enlarge for as long as the grass remains cold and wet.
Gray Snow Mold
Gray snow mold (Typhula blight) forms under snow piles, and is characterized by circular patches of matted, straw-colored turf surrounded by a white to gray halo of fluffy growth. A close examination of the infected leaves may show tiny tan or brown spheres (sclerotia) each roughly the size of a pinhead. Gray snow mold activity stops when the temperature gets above 45° F, or when the surface dries.
Pink Snow Mold
Pink snow mold (Microdochium nivale) can occur on turf with or without snow cover. It can exist in temperatures ranging from 32ºF to 60ºF as long as grass remains wet. The recent heavy snow fall has created very favorable conditions for pink snow mold, since the snow acts as an incubator for the fungus. Signs will include roughly circular, straw-colored patches of grass with a white or pinkish cast surrounding the infected area.
Treatment: What to do when snow mold is already on your lawn
Snow mold damage is generally cosmetic, and very seldom kills the entire plant. However, infected areas may be slower to come out of dormancy and green up. The best thing a homeowner or land manager can do is to give the infected patches a light raking to expose the crown of the plants. This will allow the sun to dry the plants, warm the soil, and ultimately lead to recovery. Do not aggressively rake the infected turf! This will only cause more damage to the tender roots and shoots. With warmer temperatures and dryer conditions ahead, the fungus should start to disappear on its own. In most cases, a full recovery can be expected.
Defensive Maneuvers: How to reduce the impact of snow mold next year
- Avoid fertilizing the lawn in late fall, since lush growth late in the season is more susceptible to mold attack.
- Continue mowing in the fall until the grass has stopped growing. The taller the grass, the more likely it will mat down and encourage snow mold development.
- Remove all leaves and debris before snow falls.
- Manage thatch with core aeration to help turf dry faster.
- Spread out snow piles as spring nears to encourage rapid melt.
Cynthia Ash (Revised by Chad Behrendt and Crystal Floyd), “Snow molds in lawns,” University of Minnesota Extension, 2000, accessed March 20, 2017, http://www.extension.umn.edu/garden/yard-garden/lawns/snow-molds-in-lawns/
“Pink Snow Mold on Turfgrass: Microdochium nivale,” Cornell University, College of Agricultural and Life Sciences, February 2015, accessed March 20, 2017, http://plantclinic.cornell.edu/factsheets/pinksnowmold.pdf
“Gray Mold on Turfgrass: Typhula spp.,” Cornell University, College of Agricultural and Life Sciences , February 2015, accessed March 20, 2017, http://plantclinic.cornell.edu/factsheets/graysnowmold.pdf
Sandra Mason “Receding Snow Reveals Lawn Woes,” 2014, University of Illinois Extension, accessed March 20, 2017, https://web.extension.illinois.edu/cfiv/homeowners/140220.html
A final note, my friend had some serious health complications due to the negligence of snow mold. They decided to take legal action because of it. They started their search through our location. But decided to brand out and in the end found the right option.