4 Signs It's Time To Stop Mowing Your Lawn For The Season

Garden and lawn maintenance typically slow down when the weather cools down. In the height of summer, plants grow and thrive as does the grass, requiring frequent mowing. People seeking a reprieve from tending to the lawn will be happy when temperatures drop, usually signaling a break from outdoor tasks. But when you get to wind down and store your lawn equipment depends on several factors, including geographical region, climate, and grass type. 

We spoke to three lawn experts about when to stop mowing the lawn, signs when the last cut is approaching, and why mowing in cold temperatures can harm your lawn. 

When To Stop Mowing The Lawn

As the weather cools down, plants and grass slow down their growth cycle. The grass type and where you live will influence grass growth in cooler weather. "The climate or region one lives in can greatly influence when to stop mowing," says Erin Harlow, Horticulture Extension Agent III, University of Florida/IFAS Extension Columbia County. Mowing will typically take a back seat in the colder months as some grass varieties go dormant while others slow down growth. "Many of our grasses found in lawns grow based on the soil temperature, not necessarily the air temperature," she says. "If the temperature remains warmer longer then the plants continue to grow and potentially could need to be maintained." Typically, there is a last cut or last mow of the season before temperatures drop and it's too cold to mow.  

Cool-Season Or Warm-Season Grass 

There are two types of grasses—the cool-season and the warm-season.  Geographical location will influence whether you grow cool-season or warm-season turf varieties. Warm-season grass grows in warm to hot climates and often stops growing when cold temperatures hit. "In Texas, lack of rainfall can cause turfgrass species to go dormant, as can cold freezing weather," Elizabeth McMahon, Gillespie County AgriLife Extension Horticulture Agent.

"Warm season turf grasses generally go dormant during the winter months," says Harlow. "If they are in Zones 9B -11, they may not go dormant at all."

Cool-season grass may continue to grow in cooler weather. "Cool season turfgrass may need to be maintained for a longer period of time because they continue to grow during the winter months and remain green," says Harlow. "This will, of course, depend on weather conditions." 

Geographical Region And Last Cut Of The Season 

Geographical location is a key factor when preparing for the last cut of the season. "What your climate and region is like will dictate what turfgrass species you grow, and different warm-season turfgrasses have different periods when they go dormant," explains McMahon.

If you're in a warmer region you may not have much of a break in trimming the grass compared to colder geographical areas. "In southern regions or areas with mild winters, such as Florida, Texas, or parts of California, warm-season [grass] varieties like Bermuda or St. Augustine may continue growing longer into the fall and even into winter," says Valerie Smith, Content Strategist of Sod Solutions. As long as the grass keeps growing, mowing needs to continue. "Mowing may not need to stop completely, but frequency will decrease as temperatures cool and growth slows," she says.

Where the weather is colder, plants slow down their growth or stop completely. "In cooler northern regions or areas with harsh winters, such as the Midwest or Northeast, grass growth stops earlier in the fall," says Smith.  "Cool-season grasses like Fescue or Kentucky Bluegrass, common in these regions, also slow down as temperatures drop." When the grass stops growing, usually after the first frost, mowing should stop, she says.

What To Know For The Last Cut

When you're preparing for the last cut of the season, the grass type will influence the height to trim the grass. "Mowing below the recommended height can scalp the plant, causing severe damage and stress," says Harlow. The last cut requires a balance of not cutting too short or leaving it too tall. "It is not recommended to let turf grow taller than the recommended height because it can shade itself and become thin and brown underneath," says Harlow. The best way to ensure the grass is cut and left at the proper height is to know the grass species and cut it within the recommended mowing height.

How Tall For Warm-Season Grass

Warm-season turfgrass, such as St. Augustine, should be cut between 2.5” and 4”, says Harlow. Smith recommends cutting warm-season varieties, including Bermuda, St. Augustine, and Zoysia half an inch taller than usual for the last cut. "Leaving the grass slightly taller helps protect the base of the blades and stolons from frost, creating a barrier that shields the growing areas from cold damage," she says. Avoid cutting it too short as this can leave the grass vulnerable to the cold and frost and potentially harm the lawn, she adds. 

How Tall For Cool-Season Grass

"For cool-season grasses like Fescue or Kentucky Bluegrass, the grass should be cut about half an inch shorter than normal for the final mow," says Smith. This helps the grass manage in colder temperatures and prevents matting, which can lead to snow mold, she adds. 

Signs The Last Mow Is Approaching

Several cues signal it's time for the last mow before winter: 

Check soil temperature

A practical way to know when the last cut is approaching is by checking the soil temperature. "For cool-season grasses, growth generally ceases when soil temperatures drop below 40°F (4°C)," says Smith. 

Cooler Temperatures

The weather is a good indicator that the season is shifting. "Grass growth typically slows significantly as temperatures drop," says Smith. This happens for cool-season grasses when temperatures lower. "If you notice that your grass is no longer growing rapidly, it may be time for a final mow," she says.

Falling Leaves

Leaves begin to fall with cooler weather. A visual cue is when there are plenty of leaves on your lawn. "It often signals that your lawn is entering its dormancy period," says Smith. 

Know When The First Frost Hits

The last cut should be done before the first frost comes. Weather patterns are changing so you may not be able to rely on your calendar but pay attention to frost forecasts. "It’s advisable to mow at least one week before the first hard frost hits your area," says Smith. "This helps ensure that the grass is at an optimal height for winter resilience."

Why You Don't Want To Mow In Cold Temperatures

When the weather turns cold, most plants slow down their growth or stop growing altogether until the weather warms up again. If it's cold outside, you likely prefer to be cozy indoors rather than revving up the lawn mower. The lawn also wants to be left alone. "Mowing when temperatures drop below 40°F (4°C) can severely stress the grass, " says Smith. "At these temperatures, grass growth slows significantly, and its ability to recover from mowing is compromised." This can cause grass to be more susceptible to diseases.

Grass blades are more fragile and brittle in the cold. "Mowing under these conditions can result in torn or ripped blades, leaving an unsightly lawn and increasing vulnerability to pathogens," says Smith. 

Avoid Mowing Wet or Frozen Grass

Mowing when the turf is frozen or wet can harm the grass. Once temperatures drop, leave the lawn alone. "Mowing on frozen or excessively wet soil can cause compaction, which restricts air, water, and nutrient movement to the roots," says Smith. "This compaction stresses the grass and hinders its growth potential when it resumes in the spring." Mowing in wet conditions, whether from rain, dew or frost can also create uneven cuts that can weaken the turf and make it more vulnerable to diseases, she says. 

As a rule of thumb, only mow the lawn when it's dry. Temperature is also important before you bring out the mower. "Wait until temperatures are at least 40 degrees Fahrenheit before mowing," says Smith.