Navigating lawn care during the colder months presents a common challenge for homeowners. The decision to mow in winter depends heavily on your geographic location and the type of grass you maintain. Understanding the biological state of your turf—whether it is dormant or still actively growing—provides the necessary guidance. For most regions, the goal shifts from regular maintenance to preparing the lawn to survive until spring.
The Core Decision When to Mow During Winter
Most turf varieties enter dormancy when soil temperatures consistently fall below 40 to 55 degrees Fahrenheit, halting growth. Cool-season grasses (like fescue and Kentucky bluegrass) stop growing below 40 to 45 degrees Fahrenheit, while warm-season grasses cease growth below 50 to 55 degrees Fahrenheit. Once the grass is fully dormant and has turned brown, mowing is unnecessary and can stress the resting plants, causing damage.
However, lawns in mild climates or those experiencing unseasonably warm spells may continue slow growth throughout the winter. If daytime air temperatures remain consistently above 40 degrees Fahrenheit, cool-season grasses may show enough active growth to require an occasional cut. In these circumstances, the mower should only be used when the grass shows a noticeable height increase. If your grass is not actively growing, the mower should stay stored away.
Techniques for Winter Mowing
If an occasional winter cut is necessary due to active growth, maintain a higher blade height than your standard summer setting. The grass crown, which is the growth point, needs protection from cold temperatures, and a taller blade length provides insulation. For cool-season grasses, the winter height should be set between 2.5 and 3 inches to support photosynthesis and protect the root system.
Timing the cut is equally important; avoid mowing when the grass is frozen, frosty, or saturated with moisture. Grass blades become brittle when frozen, and mowing them can cause the tissue to tear rather than cut cleanly, leading to damaged tips. Mowing on wet ground also risks severe soil compaction from the weight of the equipment, which restricts root growth and reduces the flow of water and nutrients. Cutting wet grass can also lead to clumping, which encourages the spread of fungal diseases.
Mowing frequency during warm winter breaks should be minimal, occurring only when the grass has grown enough to warrant it. Continue to follow the one-third rule, removing no more than one-third of the grass blade’s height in any single cut to minimize stress. This infrequent, higher cutting technique helps the turf maintain energy reserves while preventing excessive length.
Preparing the Lawn for Dormancy
The most impactful mowing decision related to winter is the final cut before the grass enters seasonal dormancy. This preventative measure significantly influences the lawn’s health through the cold months and into the spring. The final cut should be timed just before the ground is expected to freeze solid for the season, which varies widely by region.
For this last pass, the height should be lowered slightly below the typical growing height, aiming for 1.5 to 2.5 inches for cool-season grasses. Cutting the grass shorter helps prevent the blades from matting down under snow, which encourages the development of snow mold. The shorter height also makes the turf less appealing as a nesting site for rodents like voles, which can cause damage under snow cover.
This final short cut is distinct from any occasional, higher cuts that may occur during mid-winter warm spells. Reducing the overall mass of the grass blades before deep dormancy ensures better air circulation and reduces moisture retention that supports disease pathogens. This strategic final trim sets the lawn up to conserve energy and emerge healthier once the spring growing season begins.