The decision of when to stop mowing the lawn for the season is not dictated by a specific date on the calendar, but by environmental conditions that signal the end of active grass growth. Stopping the regular maintenance cuts at the correct time can significantly impact the health and resilience of your turf through the winter months. Properly preparing the lawn for its dormant phase ensures a faster, healthier green-up when spring arrives.
The Biological Trigger for Growth Cessation
The end of the mowing season occurs when the grass plant enters winter dormancy. This shift is primarily triggered by decreasing soil temperature, which is a more reliable indicator than fluctuating air temperatures or the date of the first frost. The soil retains heat longer than the air, meaning that grass growth can continue even after several crisp nights.
For cool-season grasses like Kentucky Bluegrass and Fescue, shoot growth—the part you mow—ceases when the 4-inch soil temperature consistently drops to approximately 40 degrees Fahrenheit. While blade growth stops, the grass plant begins shifting its energy reserves from the leaves down to the roots and crowns for winter storage. This carbohydrate storage fuels the plant’s survival through freezing conditions and supports robust growth in spring.
Regional Differences in Mowing Season Timing
Applying this biological trigger provides real-world timing that varies based on both geography and the type of grass being grown. Cool-season and warm-season varieties have different temperature thresholds for growth cessation. Cool-season grasses, which thrive in the northern states and transition zones, will continue to grow until soil temperatures drop below the 40°F mark. This often places the final mow sometime between late October and mid-November in regions like the Northeast and Midwest.
Warm-season grasses, such as Bermuda and Zoysia, found in the southern states, stop growing when the soil temperature drops to about 50 degrees Fahrenheit. In the Deep South, these grasses may enter dormancy in November, quickly turning a tan or brown color, though maintenance cuts might occasionally be needed on warmer days even into December. In transitional zones, warm-season varieties cease growth and enter dormancy well before the cool-season grasses.
Essential Steps for the Final Mow
Once the biological signs indicate the end of the growth season, the final cut requires preparation to protect the turf through winter. The most important action is adjusting the mowing height to prevent issues like snow mold and matting over the cold months. For the last cut, lower the height slightly from the usual growing-season cut to a range of 1.5 to 2.5 inches, with two inches being the target.
The shorter height prevents grass blades from bending over and creating a dense, moisture-trapping layer susceptible to fungal diseases like snow mold. Avoid scalping the lawn, which exposes the grass crown to damaging cold temperatures and weakens the root system.
Debris Removal
All leaf litter and debris must be removed from the lawn surface after this final mow. Removing this organic matter ensures the turf can breathe and reduces the likelihood of harboring pests or encouraging disease development during dormancy.