What Is Snow Mold and How To Treat It

If you live in an area with harsh, snowy winters, you know the joy melting snow can bring when it finally starts to disappear. However, sometimes the snow melt can bring unwanted spring surprises. If the snow melts in your yard and leaves behind grayish or pink patches on your lawn, you may have snow mold.

While the sight of snow mold may be alarming, homeowners can easily manage it in a few simple steps. Our guide walks you through everything you need to know about snow mold and how to restore your lawn if it becomes infected.

What’s Snow Mold?

Snow mold is a fungal lawn disease that grows on the grass in cold weather climates. It can create unsightly patches on a healthy lawn and even trigger respiratory discomfort for those with asthma or other severe allergies. Signs of snow mold usually appear in the early spring as the weather warms and the snow melts. The spores of snow mold lay dormant most of the year. However, melting snow and warmer temperatures provide the perfect environment for spores to reactivate and for the fungus to thrive.

Are There Different Types of Snow Mold?

There are two types of snow mold — pink snow mold (Fusarium patch) and gray snow mold (Typhula blight). Both types can cause damage to your grass, though pink snow mold is more serious. Pink snow mold kills roots and grass blades, making it difficult for grass to regrow after an infestation.

Symptoms of Snow Mold

While symptoms first appear as circular, straw-colored patches, you may notice:

• Patches that enlarge if the grass remains cold and damp for long periods
• The grass looking matted down inside the patch
• Colored fungal growth; gray snow mold appears whitish or gray, while pink snow mold appears whitish or pink
• The fungus fruit into mushrooms inside of the circular patches

Are Some Grasses More Susceptible to Snow Mold?

While all species of cool-season turfgrass could become infected with snow mold, some grasses get more damage than others. Here is a chart with eight types of grass to help determine if your grass is more likely to be damaged by a particular kind of snow mold.

Species of Turfgrass	Susceptible to Gray Snow Mold?	Susceptible to Pink Snow Mold?
Bentgrass	✔	✔
Kentucky bluegrass
Rough bluegrass	✔	✔
Fine fescue
Tall fescue	✔	✔
Creeping fescue	✔
Annual ryegrass	✔
Perennial ryegrass	✔	✔

What Do I Do If I Have Snow Mold?

If you see that you have snow mold, unfortunately, there is little to do to remediate it. The best course of action is to take steps to help the grass and soil dry out in affected areas. To do that, gently rake any matted grass with snow mold present — this loosens the grass and allows it to breathe and dry out more quickly.

If your grass has been infected by gray snow mold, there is a chance your grass will recover, as gray snow mold doesn’t kill the roots. If pink snow mold is present, you’ll need to clear away any dead grass and reseed affected areas.

Is There a Way of Preventing Snow Mold?

To prevent snow mold, you’ll need to prepare your lawn starting in the fall, and getting your lawn prepared before snowfall is critical for snow mold mycelium prevention. According to our research, these are some of the best lawn care tips and techniques for getting your grass ready for winter.

1. Cut grass short prior to the first snowfall.

Mowing the grass shorter than you ordinarily do is a good way to prevent the soil from trapping moisture. Cleaning up the clippings afterward also gives you the best chance of avoiding excess moisture in the soil.

2. Apply a preventative fungicide.

If your lawn is a species of grass that is more susceptible to snow mold, applying a lawn fungicide in late fall can help prevent the formation of snow mold in the spring.

3. Check for drainage issues.

If water and runoff don’t drain properly or pool in your yard, you’ll want to correct it. If melting snow cover cannot drain, moisture could build up and create the perfect environment for snow mold growth.

4. Avoid piling leaves or snow.

Piles of leaves in your yard are breeding grounds for moisture. Make sure to manage leaf litter in your yard in the late fall, and don’t leave any piles in the grass. Similarly, snow piles left from shoveling can also trap moisture. Try to disperse snow evenly when clearing driveways and walkways.

5. Remove thatch from your lawn.

Removing the thatch (the layer of dead grass and debris above the soil) a few times a year will help prevent moisture from building up. Dethatching is a deep lawn raking and aeration that allows the soil to access air and critical nutrients.

6. Let nature take its course.

Cool-season grasses naturally dehydrate in the winter, which helps in the prevention of mold growth. Resist the urge to keep your lawn lush toward the end of fall, and don’t use any fertilizers before the first snow. You’ll avoid potential snow mold problems, and your lawn will revive itself on its own time.

Restoring Your Lawn After Snow Mold

If you have a snow mold infestation, it will cease to grow once temperatures warm up — typically between 45℉ and 60℉. Soil starts to dry out in warmer temperatures, so the fungus won’t have the proper conditions to thrive.

If you want to repair brown patches of your lawn that have been affected by snow mold, you can rake up any matted patches and deposit new grass seed in those areas. Avoid giving your lawn a boost with fertilizer — it will heal itself.

Final Thoughts

The appearance of snow mold on your lawn can be a discouraging sight as spring arrives and temperatures warm up. However, it can be prevented with a few simple steps and remediated fairly easily.

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