February 18, 2021 0 Comments

Will the Mild Fall and Accumulating Snow Cause Snow Mold This Spring?

Ask Tuckahoe Turf

Will the Mild Fall and Accumulating Snow Cause Snow Mold This Spring?

As we are all aware, we have had frequent and a heavy snowfall this winter. We also had a mild late fall that ran right into our first snowstorm of the season. This combination could be a recipe for snow mold this Spring.
The amount of snow does not generally have a negative impact on our lawns. In fact, a frozen ground and the snow works as an insulating blanket that protects the below-ground living turf grass cells. However, if the ground has not completely frozen when the first snow falls, the moisture in the ground is trapped by the blanket of snow keeping the ground moist and humid. Continued snow covering works as an insulator to keep the unfrozen ground conditions consistent throughout the winter and protects it from the freezing cold air. This allows the formation and thriving of fungal diseases known as snow mold.
There are two types of snow mold: Gray Snow Mold and Pink Mold. They will present in patches of apparent dead grass ranging diameter from a couple of inches to a couple of feet.
Gray snow mold has a straw or gray color. It is far less threatening to your lawn than Pink snow mold as it only kills the blades, not the roots. Gray mold generally survives until temperatures are consistently above about 45 degrees. Then the mold dies off and new grass shoots will generally start to grow again.
Pink snow mold appears red, brown, copper or pink among the dead grass. Pink snow mold can cause severe damage to your grass’ roots, killing your turf and typically survives until temperatures raise consistently above 60 degrees.

Treatment

To start, you must remember that snow mold is a fungus and requires moisture to survive. The first step in treatment is to simply give the area a good dethatching with a rake to remove all the dead grass and any leaves that may remain from the previous fall (thatch and leaves trap moisture in the ground helping the fungus to thrive). This will allow sunlight and wind access to the affected area so it may properly dry and giving the living grass the room it needs to grow.
Mow the affected and surrounding areas shorter than usual to aid in the drying process, and shortening the lifespan of the mold, keeping the grass very short until you see growth. Make sure you rake the area thoroughly after each mow to keep the affected area as clean as possible allowing it too efficiently dry.
If your lawn has the Pink snow mold, the mold is significant or your turf just is not returning, you will most likely need to reseed (or even overseed in the late Spring). If snow mold has been a recurring issue to this point, you may want to consider Kentucky bluegrass and fine fescue as they seem to be the most resistant to the fungi. Remember not to fertilize or mow the areas you have seeded until the new grass is growing strong.

Prevention

There are several things you can do to prevent the breeding of snow mold.

  • Removal of loose grass. This includes gathering of clippings, especially late in the summer and into the fall. Dethatching as needed will allow your lawn to grow stronger in the summer months and allow the ground to dry faster before the first snowfall.
  • Keep the grass short and do not overwater in the Fall. Continue to mow your lawn, shorter than usual, if the grass continues to grow, until becoming dormant for the winter. Mold is more likely to form under longer, matted grass.
  • Remove leaves before the first snow. It is extremely important to remove as many of the leaves from the turf as possible. Leaves are a fantastic moisture barrier for your lawn and one of the best ingredients for mold growth.
  • Fertilize at the right time. Fertilizing your lawn too close to the first snow will promote the late growth of your green grass when it should be dormant in preparation for the winter. Try to apply your last lawn fertilization at least six weeks prior to the first expected snowfall.
  • Apply a fungicide if the problem is recurring. Although this is not recommended for home lawns, if you get mold rings every Spring, you may need to apply a fungicide late in the Fall to stunt the growth of the mold. In these extreme cases, a professional fungicide application is recommended.
  • Spread your snow. When shoveling walkways and driveways, try not to make piles too large on your lawn. When there are snow accumulations later in the winter that led right into warmer early Spring weather, the snowbanks from plows, driveway and walkway shoveling take longer to melt. The longer these areas are covered, the more chance there is of developing mold. As the snow is melting, it is a good idea to help break down these remaining piles and spread them out to promote quicker melting.