Switch to a dormant lawn schedule when grass growth has clearly stopped—typically when soil temperatures stay below about 50°F (10°C) for winter dormancy, or when the lawn turns brown and stops growing during summer drought dormancy. Use condition-based triggers rather than a fixed calendar date, since the exact timing varies by region, grass type, and weather patterns.
Understanding Dormancy: Winter vs. Summer
Dormancy is a survival mechanism that allows grass to pause growth and conserve energy during unfavorable conditions. There are two distinct types of dormancy, and understanding which one applies to your lawn is the first step in adjusting your care schedule correctly.
Winter dormancy occurs in cool-season and warm-season grasses alike when temperatures drop and daylight hours shorten. Cool-season grasses, such as Kentucky bluegrass and tall fescue, slow their growth dramatically in the cold, while warm-season grasses like bermudagrass and zoysia may go fully brown and stop growing altogether. Winter dormancy is triggered primarily by soil temperature, not by the calendar, so the onset can vary by several weeks from one year to the next.
Summer drought dormancy is different. It happens when warm-season grasses, and sometimes cool-season grasses, experience prolonged heat and a lack of moisture. The grass stops growing and turns brown or straw-colored as a protective response to water stress. Unlike winter dormancy, summer dormancy is reversible—the grass will green up again when rain returns or irrigation resumes. Recognizing which type of dormancy your lawn is entering helps you decide whether to stop mowing entirely or simply reduce frequency.
Condition-Based Triggers to Stop Mowing
Rather than relying on a fixed date, the most reliable way to know when to switch to a dormant lawn schedule is to watch for condition-based signals. The most important trigger is soil temperature. For most grasses, growth slows significantly when soil temperatures drop below about 50°F (10°C). Once soil temperatures stay consistently below this threshold, you can expect the grass to stop growing and enter winter dormancy.
You do not need a soil thermometer to make this call, although one can be helpful. Air temperature is a reasonable proxy: when daytime highs consistently stay below about 55°F and nights are cool, soil temperatures are likely following a similar trend. Many gardeners use the first few hard frosts of the season as a practical signal that the growing season has ended.
Visual signs are equally important. A dormant lawn stops producing new growth, so the grass stops needing regular cuts. The lawn may lose its vibrant green color and take on a duller, more muted tone. In winter dormancy, cool-season grass may stay green but simply stop growing taller. In summer drought dormancy, the lawn will turn brown and feel dry and crunchy underfoot. If you mow and the grass does not noticeably grow back within a week or two, that is a strong signal that dormancy has begun.
To distinguish dormancy from slow growth, pay attention to the trend. A slow-growing lawn in early spring or fall still produces visible new growth over a week or two, even if it is modest. A truly dormant lawn shows no measurable growth at all. If you are unsure, mow once and wait—if the grass does not need another cut for two to three weeks, it is safe to switch to a dormant schedule.
How to Adjust Your Mowing Schedule as Dormancy Approaches
The transition into dormancy is gradual, and it is wise to adjust your mowing schedule progressively rather than stopping abruptly. As growth slows in late fall, you will naturally mow less frequently. Instead of mowing weekly, you may find yourself mowing every 10 to 14 days, then every three weeks, until growth stops entirely.
This gradual reduction is beneficial because it allows the grass to build up energy reserves before dormancy. Each cut removes leaf tissue, which the plant uses for photosynthesis. By spacing out your mowings as growth slows, you leave more leaf area in place, helping the grass store carbohydrates for the dormant period and for a strong recovery in spring.
The height at which you leave the grass for winter matters. For most cool-season grasses, it is best to leave the lawn slightly taller than your summer mowing height—typically around 3 to 3.5 inches. A taller canopy shades the soil, insulates the crown of the plant, and helps protect the roots from extreme cold. For warm-season grasses, a slightly lower winter height is sometimes recommended to reduce the risk of disease in humid climates, but a moderate height is generally safer than scalping.
As you take your final mowings of the season, lower the mower deck gradually rather than making one drastic cut. This respects the one-third rule and avoids stressing the grass right before it enters dormancy. The goal is to enter dormancy with a healthy, well-nourished lawn, not a stressed one.
Caring for a Dormant Lawn
Once your lawn is fully dormant, the care routine changes significantly. The most important rule is to avoid overwatering. A dormant lawn needs far less water than an actively growing one. In winter dormancy, the lawn typically needs little to no supplemental watering, as natural rainfall and cooler temperatures keep the soil adequately moist. Overwatering a dormant lawn can saturate the soil, encourage disease, and waste water.
During summer drought dormancy, the situation is slightly different. The grass is dormant specifically because of a lack of water, so it may need occasional irrigation to survive an extended dry spell. However, the goal is not to green the lawn up but to keep the crowns and roots alive. A deep, infrequent watering—about once every two to three weeks during severe drought—is often enough to sustain dormant grass without encouraging it to break dormancy prematurely. Frequent, shallow watering is counterproductive, as it encourages shallow roots and can promote disease.
Foot traffic is another consideration. A dormant lawn is more fragile than an actively growing one. The crowns and roots are alive but not actively repairing damage, so heavy foot traffic can compact the soil and damage the grass. It is best to limit traffic on a dormant lawn, especially during winter when the soil may be frozen and the grass is brittle. If you must walk on it, try to vary your path to avoid creating worn trails.
Occasional mowing of a dormant lawn is generally not necessary, since the grass is not growing. However, if leaves or debris accumulate on the lawn, it is a good idea to remove them. A thick layer of leaves can smother the grass and trap moisture, inviting disease. Raking or using a leaf blower to keep the lawn clear is a better use of your time than mowing.
When to Resume Regular Mowing
Knowing when to switch back to a regular mowing schedule is just as important as knowing when to stop. The signals for the end of dormancy mirror the signals for its onset. In spring, as soil temperatures rise above about 50°F (10°C) and daylight hours lengthen, grass begins to grow again. You will notice a subtle greening and the appearance of new growth, even if it is slow at first.
For cool-season grasses, this typically happens in early to mid-spring, depending on your region. Warm-season grasses come out of winter dormancy later, once soil temperatures are consistently warmer. In summer drought dormancy, the lawn resumes growth when moisture returns—after a significant rainfall or when you resume regular irrigation. The grass will gradually green up from the crown outward as it recovers.
When you see consistent new growth, it is time to resume mowing. Start with a light mow at a slightly higher setting than your normal summer height, then gradually lower the deck over the next few mowings. This gradual approach gives the grass time to adjust and avoids scalping the newly emerging growth. Resume your regular mowing frequency once the lawn is growing at its normal spring or summer pace.
The key takeaway is to let the lawn, not the calendar, tell you when to switch schedules. By watching soil temperatures, growth patterns, and visual cues, you can time your transition into and out of dormancy correctly, keeping your lawn healthy through every season.
