Watch Out for These Winter Lawn Funguses in Western Washington
By Cody Cochran | December 2025
Our cool, wet winters are prime time for a few lawn diseases, but not all the usual suspects are worth losing sleep over. Here’s what actually shows up this time of year — and one you can pretty much ignore.
1. Pink Snow Mold (Microdochium Patch)
Circular, straw-colored patches 4–12 inches wide, often with a pink or whitish edge when it’s soaking wet. Worst after light snow or under piles of wet leaves.
2. Gray Snow Mold (Typhula Blight)
Grayish-white crusty patches up to 2 feet across with tiny tan/black “pepper specks” in the dead grass. Shows up under heavy leaf cover or in shady spots.
3. Fusarium Patch / Microdochium Patch (no snow needed)
Small orange-brown spots that merge into bigger blighted areas, sometimes with a faint pink/orange halo in the morning dew. This is the one we fight most winters.
What to Look For Right Now
Patches that stay matted and wet longer than the rest of the lawn
Slimy or greasy feel to the blades
Pink, white, or gray crust at the edges in the morning
Circles that keep growing even with light traffic
The One You Can Ignore: Red Thread / Laetisaria fuciformis
You’ll probably see a few pinkish-red threads or small irregular patches this winter — totally normal here. Red thread loves cool, humid weather and low nitrogen, but it almost never kills the grass in Western Washington. It looks ugly for a few weeks, then the lawn outgrows it as soon as we get a little warmth and fertilizer in spring. No treatment needed 99% of the time.
Quick Action Steps for the Real Problems
Rake and remove wet leaves ASAP.
Lightly rake crusted patches to improve airflow.
Hold off on heavy nitrogen until March.
If snow mold hits hard every year, a single preventive fungicide in late October/early November usually solves it.
Most winter diseases here are cosmetic and bounce back fast once the sun shows up. Spot anything weird? Shoot us a photo — we’ll let you know if it’s worth worrying about.
Please contact us today if you have questions or want a free estimate.