When Does Grass Stop Growing Each Season?
Put away the mower when your grass settles down for a long winter's nap
Grass stops growing when the temperature is below 40 to 55 degrees Fahrenheit and above 90 to 100 degrees Fahrenheit.
The exact temperatures that prevent grass growth depend on where you live, the type of grass, and your lawn health.
Grass dormancy is normal and does not mean that your grass is dead.
Breaking out the mower each week can become a bit of a bear by the end of the summer. So, when does grass stop growing, and when can you look forward to a bit of a lawn care respite? Depending on the type of grass, where you live, and the health of your lawn, assume that your grass will slow its growth at the height of summer and around the first frost of the season.
When Does Grass Stop Growing?
Grass stops growing when it enters its dormancy phase—a normal process where the crown of the grass stops growing to reserve energy, similar to a tree losing its leaves. In general, expect grass to stop growing from the late fall to early spring and for a moment at the peak of summer. A few scenarios trigger dormancy, such as extreme temperatures, low amounts of water, long periods of low sunlight, or poor soil health.
Factors That Affect Grass Growth
Understanding when the grass stops growing can affect how you build your landscaping care plan or budget for the cost of lawn care for each season. It'll also save you from the stress of thinking that your low-growing and even browning grass has died.
Grass Variety
Always begin by determining the type of grass in your yard. Cool-season grasses primarily flourish in the north and central planting zones of the country while warm-season grasses—you guessed it—thrive in warmer, more southern climates.
Cool-Season Grasses
Cool-season grasses prefer balanced temperatures from 55 to 75 degrees Fahrenheit, depending on the type of grass. Growth will typically stop altogether below 40 and above 90 degrees Fahrenheit, entering a dormancy phase. Common cool-season grasses include Kentucky Bluegrass, Perennial Ryegrass, and fine fescue.
Warm-Season Grasses
If you live in a Southern or transition planting zone of the U.S., warm-season grasses will have an easier time growing. Popular varieties include St. Augustine grass, centipede grass, and Zoysiagrass, which can thrive and continue to grow in temperatures up to between 95 and 100 degrees Fahrenheit. That being said, they'll struggle if your area has an unseasonal cold snap, going dormant below 55 to 60 degrees.
Location
Unsurprisingly, planting the wrong grass for your region could set off your lawn's dormancy phase for much longer than you prefer. This could mean brown, straw-like grass in the winter while your neighbor's lawn remains relatively green.
Additionally, the microclimate of your area will sway grass growth. Factors such as local humidity, the sea salt content of the air, and the amount of sunlight each season will play a role in your grass growth.
Soil Temperature
If you're tracking grass growth closely, make the call about whether to mow by monitoring your soil temperature. Even when the air temperature fluctuates during the shoulder seasons, it's your soil temperature that has the greatest effect on its dormancy. Cool-season grasses require a soil temp over 55 degrees Fahrenheit, while warm-season grasses prefer soil over 70 degrees Fahrenheit.
Lawn Health and Design
As a plant that craves sunlight, water, and nutrients, your lawn design plays a part in dormancy as well. Grass requires a balance of sunlight and shade, well-draining soil, and plenty of space from nutrient-hungry weeds. Hiring a local lawn care professional can help you avoid brown patches of grass as the seasons change.
When Should You Stop Mowing the Lawn?
The last mow of the season directly relates to when your grass stops growing. Once you determine what type of grass or grass blend you have in your lawn, keep a close eye on the weather report. Prepare to winterize your lawn when air temperatures consistently fall below the dormancy level for your type of grass or when the first frost warning arrives on the forecast.
It is smart to avoid mowing during a heat wave that pushes consistent air temperatures over the high threshold. When you mow in the heat, the timing of cutting your grass matters as well. Stick to the mid-morning hours between 8 a.m. and 10 a.m. after the morning dew but before the hottest time of the day.
Frequently Asked Questions
Your grass-growing schedule depends on where you live and the variety of grass in your lawn. Cool-season grasses typically stop between November and April with a slowdown at the peak of summer. Warm-season grasses will slow when temperatures drop below 55 degrees Fahrenheit in December and January. Hiring a great lawn care team can help you pinpoint the right moment to cut back on mowing.
Cut your lawn a bit shorter before the winter, typically between 2 and 2½ inches, depending on the variety of grass. On average, the best height to cut grass typically falls between 2 and 3 inches throughout the year. Aim for the shorter side of this range when you mow for the last time of the year to avoid common winter lawn diseases and moisture issues.
Stop watering your lawn after the soil freezes for the season. You should continue to water your lawn throughout the fall, but stop once your grass goes dormant for the year. You can begin to space out how often you water your lawn as the first frost approaches, depending on where you live in the country.
