| Key Takeaways |
|---|
| • Grass stops growing at 55 degrees F or below: This air temperature threshold signals that dormancy is setting in for the season. • Grass types grow in different temperature ranges: Warm-season grasses in USDA zones 7-10 grow when soil is above 70 degrees F, while cool-season grasses in zones 5-9 grow in temperatures of 55 to 65 degrees F. • Peak growth has its own sweet spot: Warm-season grasses grow fastest between 75 and 90 degrees F, while cool-season grasses peak between 60 and 75 degrees F. |
Grass growth generally stops once temperatures fall to about 50 to 55 degrees or below. The biggest factor is your turfgrass type, whether it is cool-season or warm-season.
Below, we cover when each grass type stops growing, how temperature and location shape the timing, how to tell dormant grass from dead grass, and how to handle your last mow of the season.
Timing that final mow and reading your lawn’s dormancy signals take attention all season, which is why many homeowners let LawnStarter lawn mowing pros keep the schedule on track for them.
When Does Grass Stop Growing for the Year?
Most lawns stop producing enough top growth to require regular mowing sometime between October and December, but the timing varies by region, grass type, and weather.
| Region | Typical Slowdown or Dormancy Window |
| Northern states | Late October to November |
| Transition zone | November to early December |
| Upper South | October to November for warm-season grasses |
| Deep South | November to December, if the lawn goes fully dormant |
Cool-season lawns generally remain active later into fall than warm-season lawns.
When Cool-Season Grasses Stop Growing
Cool-season grasses generally stop growing once temperatures fall below 50 degrees, though in mild-winter areas they may stay active all season. They are adapted to tolerate lower temperatures and less sunlight, so they stay green and keep growing later into the year.
Here are some of the most popular cool-season grasses and when they stop growing based on the temperature outside:
| Grass Type | Stops Growing Below | Stops Growing Above |
| Fine fescue | 50 degrees | 90 degrees |
| Tall fescue | 50 degrees | 90 degrees |
| Kentucky bluegrass | 50 degrees | 80 degrees |
| Perennial ryegrass | 40 degrees | 86 degrees |
When Warm-Season Grasses Stop Growing
Most warm-season grasses stop growing once temperatures fall below 55 degrees and go dormant in late fall. They are the powerhouses of heat and humidity, best suited for southern or coastal states, but they are not very cold-tolerant.
Here’s when you can expect the most popular warm-season grass varieties to stop growing, based on the temperature outside:
| Grass Type | Stops Growing Below | Grows in Heat Up To |
| St. Augustinegrass | 55 degrees | 100 degrees |
| Bahiagrass | 50 degrees | Thrives above 80 degrees |
| Bermudagrass | 50 degrees | 100 degrees |
| Centipedegrass | 55 degrees | 95 degrees |
| Zoysiagrass | 55 degrees | 95 degrees |
| Buffalograss | 50 degrees | 95 degrees |
| Carpetgrass | 50 degrees | 90 degrees |
How Temperature Affects Grass Growth
Cold weather slows us down, and it does the same to our grass. “Most plants utilize cooler weather to ‘harden,’ because they slow down their own growth (naturally) and prepare their tissues and roots for freezing temperatures,” says Tyler Mainka of Best Bark Mulch in Pewaukee, Wisconsin.
Every species of grass has a specific temperature range in which it’s most active. As soon as temperatures fall below or rise above that range, the growth of the grass starts slowing down.
When temperatures continue to drop consistently leading into winter, the grass eventually goes into dormancy or hibernation mode, which lasts until springtime.
During this hibernation, the grass will grow very slowly or not at all. It may even fade to tan or brown, but it’s not dead, and it should green up when temperatures rise again.
Soil Temperature
Soil temperature is the single most critical variable regarding grass growth. Temperature variations will increase or decrease essential nutrients available for plant maintenance and defense mechanisms, like water uptake, decomposition of carbon dioxide, and photosynthesis, all things needed for healthy growth.
In cold weather, grass conserves energy by going dormant. This protects the delicate crown from extreme temperatures and provides an optimal environment for the plant to survive until better conditions arrive.
Grass can go dormant due to extreme heat, too. If daily temperatures have been topping out at levels significantly higher than normal for your area, the lawn may look dry and brown.
Air Temperature
Soil temperature and air temperature are two different things. The temperature your weather app shows is the air temperature, and the soil beneath your lawn usually runs cooler and changes more slowly.
Cool-season grasses grow best when the air is about 65 to 75 degrees, while their roots do best at soil temperatures roughly 10 degrees lower, around 55 to 65 degrees.
For a more accurate reading, push a soil thermometer a few inches into the ground in the morning and check it over several days.
Dormant Grass vs. Dead Grass
When grass stops growing and turns brown, it is easy to fear the worst. In most cases, though, your lawn is only dormant, not dead. Dormant grass is simply resting, conserving energy until warmer weather returns, while dead grass will not come back no matter what you do.
A few simple checks help you tell the difference. Dormant grass usually turns an even tan or light brown across the whole lawn and stays firmly rooted.
Dead grass tends to show up in scattered patches and pulls up easily with a gentle tug.
“I let the customer know that it’s OK if your yard goes dormant; it’s not killing it. It’s a normal, natural process,” says LawnStarter pro Justin Stultz of Wildflower Lawn Care in Hutto, Texas.
If most of your lawn browned out at the same time as the weather changed, dormancy is the likely answer. Give it consistent care, and it should green up once the season turns.
See Related: Dormant Grass or Dead Grass? How to Tell the Difference
When and How to Do Your Last Mow of the Season
Now that you know when your grass stops growing, you can plan your last mow of the year accordingly. Pay attention to the daily temperature, and when it consistently drops to 50 to 55 degrees, it’s time to prepare your lawn for winter dormancy.
When mowing the lawn for the last time for the season, you can either:
Mow the lawn at its usual height: Keep the same height you’ve been using all autumn to help prevent winter lawn diseases like snow mold and reduce thatch buildup.
Mow a bit lower than usual: A slightly shorter final cut strengthens the grass’s root system and helps prevent weeds. Just avoid scalping the lawn, and never remove more than one-third of the blade in a single mow.
Both of these methods, mowing low or keeping a regular height, are advocated by different lawn care pros and experts. Check out our article on the mowing height debate for more information.
Choose whichever is most suited to your lawn’s specific concerns: Is your lawn more prone to weeds or fungal diseases? Do you usually see excessive thatch buildup in winter? Or does your grass need a deeper root system?
You’ll also want to sharpen your lawn mower blades before the last mow of the season. Using dull blades can leave jagged edges that create an open path for winter diseases.
A sharp lawn mower blade will create a smooth, clean cut that helps your grass retain moisture and prevents damage from extreme cold.
See Related: How to Winterize Your Lawn
FAQs
Warm-season grasses typically found in USDA hardiness zones 7-10, such as Bermudagrass, grow when the soil temperature is above 70 degrees. Cool-season grasses found in USDA hardiness zones 5-9 flourish when air temperatures reach 55 to 65 degrees.
Grass does grow faster if you fertilize it at the right time, as most fertilizers contain essential nutrients for healthy growth:
• Cool-season grasses should be fertilized in early spring and fall when temperatures are cooler.
• Warm-season grasses should be fertilized in early spring and summer, when they are actively growing.
Fertilizing your grass during its dormant season will not make it keep growing or grow any faster. In fact, fertilizer could harm your grass at this time and encourage winter weeds to take over.
Peak grass growing season varies by grass type. Warm-season grasses grow most actively in late spring and early summer, when temperatures are above 75 degrees but below 90 degrees.
Cool-season grasses grow most actively in spring and fall, when temperatures are above 60 degrees but below 75 degrees. While both grass types can grow outside these ideal ranges, they grow fastest under these conditions.
In most regions, grass does not actively grow in winter; it goes dormant to survive the cold. It resumes growth once soil temperatures climb back above about 50 to 55 degrees in spring, though lawns in very mild climates may grow slowly year-round.
When to Call a Lawn Care Professional
The true masters of tending to a lawn understand that whatever the weather, it pays to undertake certain tasks throughout the year, from sowing and fertilizing in spring to mowing regularly in summer and preparing for the winter months in fall.
LawnStarter helps homeowners find the right local mowing pros so they can enjoy a green and healthy lawn no matter what the seasons bring. With quick and easy access to reliable professionals, you can make sure the grass keeps growing right up until it’s time to go dormant.
Main Image: A manicured backyard glows in warm golden sunlight, showcasing a lush lawn bordered by a neatly trimmed flower bed and shrubs. Photo Credit: Banu / Adobe Stock
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