Fall Mowing Height: Protect Your Lawn Through Winter

As summer fades, a common debate arises: should you cut the lawn short for winter or leave it longer? If you're in the Seattle area with a cool-season lawn that's a bit thin and mossy, the answer leans toward keeping it taller—and here's why.

Leaf Area Fuels Root Growth

Grass continues photosynthesizing during winter whenever temperatures allow. More leaf surface means more energy production, which translates to stronger root development. Scalping the lawn—mowing extremely short—depletes the plant's reserves just when it needs them most.

Moisture Retention Matters

Winter winds and low humidity can dry out exposed soil surprisingly fast. A taller canopy shades the soil, reducing evaporation and protecting crowns from temperature extremes. This is especially important in the Pacific Northwest, where winter rainfall doesn't always prevent surface drying.

Consistent Height Year-Round

For bluegrass and fescue lawns, maintaining a 3- to 4-inch mowing height throughout the year works well. This isn't the approach for warm-season grasses like Bermuda, St. Augustine, or centipede, which have different dormancy patterns.

Thicken the Stand Now

Early fall is the ideal time to overseed thin areas and apply a balanced fertilizer. The combination of warm soil, cooler air, and reliable moisture gives new seed the best chance to establish before winter.

Resist the urge to scalp. A taller lawn heading into winter emerges thicker and healthier in spring.