When Does Grass Stop Growing?

When grass stops growing depends on what type of grass you have. Generally speaking, warm-season grasses stop growing from fall to spring, and cool-season grasses stop growing in the winter and the summer. However, several factors affect grass growth, including temperature, location, moisture, and growing conditions.

Temperatures when grasses stop growing

The main reason grass stops growing is temperature extremes. When the weather becomes too hot or cold, turfgrass turns brown and enters dormancy to protect itself and conserve resources. It may look dead, but it’s not.

However, heat and cold don’t affect all grasses equally. Warm-season grasses are more tolerant of high temperatures and less tolerant of low temperatures. On the other hand, cool-season grasses go dormant in hot weather while tolerating colder temperatures. 

Note: Just because your grass stops growing doesn’t mean it can’t survive more extreme temperatures.

Warm-season grasses

If you live in the bottom half of the U.S., you probably have warm-season grasses. These species generally go dormant when the average air temperature drops below 50 to 55 degrees Fahrenheit. While warm-season grasses handle heat well, they can stop growing when temperatures rise above 90 degrees Fahrenheit.

Here’s a temperature breakdown for the most common warm-season grasses:

Grass type	Stops growing below this temperature (Fahrenheit)	Stops growing above this temperature (Fahrenheit)
Bahiagrass	50°	86°
Bermudagrass	50°	100°
Buffalograss	50°	90°
Carpetgrass	60°	90°
Centipedegrass	55°	95°
St. Augustinegrass	55°	95°
Zoysiagrass	50°	95°

Cool-season grasses

If you live in the top half of the U.S., you likely have cool-season grasses. These grass varieties typically stop growing when temperatures climb above 75 degrees Fahrenheit. Though they can survive colder temperatures, cool-season grasses typically stop growing below 40 degrees Fahrenheit.

Here’s a chart showing what temperatures each common cool-season grass stops growing at:

Grass type	Stops growing below this temperature (Fahrenheit)	Stops growing above this temperature (Fahrenheit)
Fine fescue	34°	85°
Kentucky bluegrass	32°	85°
Perennial ryegrass	32°	80°
Tall fescue	37°	90°

Time of year when grass stops growing

The U.S. has such a varied climate that there’s no universal start and stop date for grass growth. However, we can provide some general dates based on regions of the U.S.

Region of the U.S.	Warm-season grass	Cool-season grass
Northeast	October through May	November through April and July through August
Southeast	November through March	January through February and July through August*
Midwest	October through April	November through March and July through August*
Northwest	November through May	November through February and July through September*
Southwest	November through February	June through August*

*If not irrigated properly (more on that in the next section).

Given the length of some of these dormant periods, you can see why not all grass types are suited for every climate. For example, warm-season grass won’t grow for long in the Northeast, so it’s better to stick with cool-season grasses. However, there are some exceptions if you live in the transition zone where both cool and warm-season grasses grow.

How water affects grass growth

Even when temperatures aren’t too extreme for your grass, it can go dormant due to lack of water. Remember, dormancy is a lawn’s survival mode — it stops growing to conserve resources and endure drought.

As your lawn’s caretaker, you have two options: 

1. Enjoy the break from lawn care. Many turfgrass experts and water companies encourage homeowners to let their grass go dormant, particularly in the summer heat. It may not look pretty, but you won’t have to mow or pay an astronomical water bill to keep it green and growing. Plus, it will bounce back once it starts raining again.
2. Revive it with water. If a green lawn is important to you, make up for the weather’s shortcomings. The best time to water in hot weather is between 5 a.m. and 9 a.m. to reduce evaporation. However, it’s possible for it to be too hot for irrigation.

Once the dry season is over, check out our guide, “How to Help Your Lawn Recover from Drought.”

Note: Keep in mind that overwatering also can stunt your grass’ growth. If you’ve been watering and your grass still won’t grow or turn green, try to dial it back. Check out our guide, “When and How to Water Your Lawn”, for more details.

Other reasons your grass stops growing

Temperature, time of year, and water are the main reasons your grass stops growing. Here are some other factors that could cause your grass to stop growing:

• Disease, weed, or pest infestation: Your grass can’t put its energy into growth if it’s fighting these threats.
• Nutrient deficiency: Nitrogen, phosphorus, and potassium are crucial for grass growth. Get a soil test to see if your grass is missing these necessary nutrients.
• Improper mowing: If you cut your grass too short, you may stunt its growth. Mow at the proper height for your grass.
• Soil compaction: Your grass may struggle to grow if the soil is compacted due to excessive foot traffic or too much water.
• Unbalanced pH: If your soil is too acidic or alkaline, your grass will struggle. You can change soil pH with amendments.
• Lack of sun: Grass needs photosynthesis to grow, and your yard may not provide enough sunlight. To solve this problem, you can cut back plants to reduce shade or switch to a shade-resistant grass type.

FAQ about when grass stops growing

How can you tell if grass is dormant or dead?

People often call any brown or yellow grass dead, but there is a difference. A dormant lawn will turn green and grow again once temperatures mellow out or you water it. Dead grass won’t recover, even after things return to normal.

What temperature kills grass?

According to Turfax, the lethal threshold for grasses is based on tissue temperature rather than air temperature. Even if the air is hotter or colder than the temperatures below, your grass could survive if the grass is well insulated.

• Warm-season grasses die when tissue temperatures rise above 110 to 120 degrees Fahrenheit or below 31 to 20 degrees Fahrenheit. 
• Cool-season grasses die when tissue temperatures rise above 104 and 112 degrees Fahrenheit or below 26 to -20 degrees Fahrenheit.

When does grass grow the most?

Warm-season grass grows the most in summer when temperatures are between 80 and 95 degrees Fahrenheit. Cool-season grass grows best in spring and fall when temperatures are between 69 and 75 degrees Fahrenheit.

How does grass growth affect my lawn care schedule?

When your lawn isn’t growing, it needs little attention. You also need to be more careful with it.

• Stop mowing: Mowing your grass when it isn’t growing will only stress it out. Give you and your grass a break.
• Don’t fertilize outside of the growing season: Your grass either won’t absorb it, or the fertilizer will trigger new growth that’s too vulnerable to temperature extremes and drought.
• Wait to aerate: While beneficial, aeration is an invasive procedure. The best time to aerate is when the grass is actively growing so it can recover quickly. 
• Keep foot traffic low: Dormant grass won’t recover from foot traffic, and it’s easily damaged in freezing weather. 

Your grass needs the most attention when it’s growing.

• Mow and irrigate regularly: Keep your growing grass manageable and hydrated.
• Fertilize and aerate when needed: When it’s growing, your grass can make the best use of fertilizer and bounce back from aeration.

For more information on how growth and dormancy affect your lawn care schedule, check out these guides:

• “Lawn Care Calendar for Warm-Season Grass”
• “Lawn Care Calendar for Cool-Season Grass”

Want grass to grow? Call a pro

Grass growth is a complicated equation based on temperature, amount of water, and growing conditions. If you’d rather not track its growth, hire a professional to do it for you. Lawn Love can connect you with local lawn care pros who know all about grass growth, dormancy, and lawn treatment schedules. 

• Main Photo Credit: lovelyday12 | Adobe Stock Free | License