How to Spot and Get Rid of Snow Mould

The snow has finally melted, revealing your lawn in all its post-winter glory…except, instead of lush green grass, you’re met with patchy, matted areas covered in white or yellowish fuzz.

There’s no need to panic; your lawn isn’t dying. It’s probably snow mould, a common fungal disease that thrives in cold, wet conditions. It appears as circular patches of matted grass, sometimes with a web-like coating of white or pinkish mould.

The fungus becomes visible as snow thaws, but snow isn’t always necessary for it to develop. The good news? Most cases only affect grass blades, meaning your lawn can recover with the right care.

What is Snow Mould, and How to Identify It?

Snow mould is a cold-weather fungal disease that thrives under prolonged snow cover and damp conditions. When snow sits on the lawn for too long without proper airflow, it traps moisture, creating the perfect breeding ground for fungal spores.

While it’s most common in early spring, snow isn’t always required for it to develop. Excess thatch, compacted soil, and leftover fall leaves can also create the ideal environment for infection.

There are two types of snow mould:

• Grey Snow Mould: More common and less severe, affecting only grass blades without damaging the roots.
• Pink Snow Mould: The more aggressive variety, which can kill grassroots, leading to long-term damage if untreated.

How to Spot Snow Mould

Once the snow melts, you’ll notice these signs:

• Circular, mouldy patches. These range from grey to pink hues, often appearing in irregular, overlapping rings. The patches can start small and expand, creating a patchwork effect across the lawn. In severe cases, the affected areas may feel spongy underfoot.
• Matted or slimy grass. The affected areas feel damp, sticky, or flattened, making them stand out from the rest of the lawn. In some cases, the grass blades may stick together, forming dense clumps that are difficult to separate.
• A musty or mildew-like smell. A stale, earthy odour can accompany snow mould, especially in areas with thick thatch build-up. If the smell lingers after raking, it could indicate fungal spores are still present, requiring further drying and treatment.
• Thin or dead patches. If pink snow mould is present, you may notice bare spots where the roots have been damaged. These areas may struggle to recover on their own, requiring overseeding to restore thickness.
• Web-like fungal growth. In humid conditions, you might see a fine, cotton-like layer of mould spread across the grass. This fungal growth may disappear as the lawn dries out, but if left unchecked, it can spread deeper into the turf.
• Delayed green-up in affected areas. Snow mould weakens grass, meaning infected patches take longer to regain colour and strength compared to the rest of the lawn. If parts of your lawn stay dull and lifeless long after spring arrives, it could be a lingering sign of snow mould damage.

Step-by-Step Guide to Treating Snow Mould in Regina

If snow mould has made an unwelcome appearance on your lawn, don’t panic—it’s treatable. Here’s how to do it:

Step 1. Rake and Fluff Up the Affected Areas

• Your lawn has been smothered under a snowy blanket for months, so it’s time for a little wake-up stretch.
• Gently rake over matted grass to break up compacted areas and increase airflow. This helps dry out the fungus-friendly environment.
• Avoid going full lumberjack with your rake, though—over-aggressive raking can rip up healthy grass, leaving your lawn bald and embarrassed.
• A leaf rake or dethatching rake is your best bet to lift flattened blades without disturbing the roots too much.

Step 2. Improve Air Circulation & Dry Out the Lawn

• Sunlight is your best friend, so let it do its thing. Allow the natural warmth and airflow to dry out affected areas.
• If there are leftover piles of snow, grab a shovel and gently spread them out to help them melt faster and prevent further moisture build-up.
• Avoid early spring watering because the lawn needs time to recover and dry out naturally before you add extra moisture.

Step 3. Aerate the Lawn for Better Drainage

• Does it feel like your lawn is holding water like a sponge? That’s compacted soil for you. Compacted soil traps moisture, making it harder for affected areas to dry out.
• Core aeration loosens things up and helps break up soil compaction, improving drainage and oxygen flow.
• It also encourages strong root growth, which makes your lawn more resilient against future fungal infections.

Step 4. Overseed Bare Patches

• If pink snow mould has caused significant root damage, overseeding is essential to fill in thin or bald spots with fresh, healthy grass.
• Choose a mould-resistant grass blend suitable for Regina’s climate. Look for disease-tolerant varieties like Kentucky bluegrass, perennial ryegrass, or fescues.
• Lightly rake the soil before seeding to improve seed-to-soil contact, then keep the area moist while new grass is established.

Step 5. Apply Organic Fertilizer

• A slow-release, organic fertilizer gives the lawn a nutrient boost without excessive nitrogen, which can actually encourage fungal growth.
• Compost or natural fertilizers like seaweed or alfalfa-based blends help restore soil health without harming beneficial microbes.
• We recommend applying fertilizer in early spring once the lawn starts actively growing to support healthy regrowth. Your GreenKeeper directly applies our new and improved season-long fertilizer treatment to your lawn. Essential nutrients like potassium and sulphur are always included for optimal health.

Step 6. Monitor and Water Wisely

• Snow mould should clear up as temperatures rise and the lawn dries out—but keep an eye on affected areas.
• Water only when needed, making sure the lawn dries out between watering sessions to prevent lingering moisture.
• Avoid watering in the evening, as cooler temperatures and wet conditions create the perfect environment for fungal resurgence.
• If your lawn remains persistently damp, improve drainage by aerating compacted areas to promote better water absorption.

How to Prevent Snow Mould Next Season

Snow mould is easier to prevent than to treat, and a few simple steps during the year can reduce the risk of fungal outbreaks. Here’s how:

• Mow at the Right Height Before Winter: Keep grass slightly shorter than usual for its last mow before snowfall, but don’t scalp it, as that can stress the roots.
• Remove Leaves & Debris in Fall: A cluttered lawn traps moisture, creating the ideal conditions for fungal spores to thrive under snow. Regular raking helps prevent this.
• Aerate the Lawn in Fall: Compacted soil holds excess water, increasing the risk of snow mould. Core aeration before winter helps improve drainage and airflow.
• Apply a Preventative Fungicide: If snow mould is a recurring issue, consider applying a fall fungicide treatment. Choose eco-friendly, lawn-safe options to minimize chemical impact.
• Avoid Excess Nitrogen in Fall Fertilization: High-nitrogen fertilizers encourage late-season growth, which is more vulnerable to fungal infections. Opt for a winterizing fertilizer with balanced nutrients instead.
• Improve Drainage and Snow Distribution: Ensure your yard has proper drainage to prevent water pooling. Avoid large snow piles in shaded areas, as they take longer to melt and trap moisture.

Let’s Mow Past the Mould

Snow mould had its moment, but it’s time to show it the door. With a little TLC (and maybe some help from our GreenKeepers), your lawn will be spring-ready in no time.

We bring you lawn care packages that give your yard expert care all season long, along with individual services like aeration, overseeding, and fertilization to revive lawns across Regina, Winnipeg, Red Deer, Edmonton, Saskatoon, and Calgary.

Get a free estimate, and let’s kick that fuzzy fungus to the curb!