How Often Should I Mow My Lawn?

“Once per week” is generally the answer to how often you should mow your lawn; however, this response does not address the real question. The question of lawn mowing frequency is actually a question of grass length. Different grass types have different length requirements, and certain external factors will cause these different grasses to grow at varying rates. Excessive rainfall or too much fertilization could lead to more frequent mowings, but persistent drought conditions could result in less frequent grass cutting sessions. To understand how often you should mow your lawn, you must first understand your grass!

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When Should I Mow Cool-Season Grass?

Just as one would assume of turf in this category, cool-season grasses thrive in cooler temperatures. Spring and fall are the seasons during which cool-season lawns will see maximum growth. Especially during times of heavy spring rainfall, your cool-season lawn will need to be mowed more frequently during the cooler months in spring and fall. Cool-season grasses do not do as well during the damaging heat of summer. In hot and dry conditions, cool-season lawns will require less frequent mowing, sometimes as infrequently as once every two weeks or so.

The table below shows the optimal heights for various cool-season turfs, as well as the height at which each specific type should be cut. How often you should mow depends entirely on how long it takes your turf to grow from its optimal height to a proper mowing height.

Cool-Season Grass

Optimal Height (inches)

When To Mow (inches)

Perennial Ryegrass

1.5 - 2.5

2 - 3.75

Kentucky Bluegrass

2 - 2.5

3 - 3.75

Fine Fescue

2 - 2.5

3 - 3.75

Tall Fescue

2 - 3

3 - 4.75

When Should I Mow Warm-Season Grass?

Determining when to cut warm-season grass is a similar process to cutting cool-season grass, except the peak seasons are reversed. Warm-season lawns are much more equipped to handle the stress of the summer sun, but they tend to struggle in colder temperatures during early spring and fall. As such, warm-season lawns need to be cut most frequently in summer, but frequency should be reduced when temperatures drop and grass growth becomes much slower.  

Warm-season grasses are generally kept at shorter heights because they require more sunlight. Hot, rainy days will also lead to rapidly growing warm-season turf, which means some lawns may occasionally need to be mowed twice per week to maintain optimal height.

Warm-Season Grass

Optimal Height (inches)

When To Mow (inches)

Bermudagrass

1 - 1.5

1.5 - 2

Zoysia

1 - 1.5

1.5 - 2

Centipede

1.5 - 2

2 - 3

St. Augustine

2.5 - 3

3.75 - 4.5

What Is The One-Third Rule?

The one-third rule of lawn mowing is simply a guideline to tell you how much grass should be removed with each cutting. Once your lawn is well established into its growing season, the general rule is not to remove more than the top third of your lawn’s length. Cool-season grasses grow earlier in the year than warm-season grasses, so they will be established quicker than warm-season lawns. Regardless of turf type, once your lawn is easily growing within its optimal height range, removing only the top third will prevent turf burn and help you maintain a lush lawn.

The one-third rule should be applied even when grass grows taller than expected due to heavy rainfall, a skipped mowing session, excessive fertilizing, or any other reason. For these situations, you may need to mow a bit more frequently in order to get your lawn back to its optimal height. Remember to keep mowing limited to twice per week at maximum, or you will run the risk of damaging your turf. It may be tempting to simply set your mower blade low immediately after your lawn grows too tall, but following the one-third rule is the healthiest way to get your lawn back in shape!

We hope you enjoyed this blog post. Below you can find more lawn mowing facts and questions and if you're looking for more information on how to prevent your trampoline from roasting your lawn , check out our blog post linked here.

Did your lawn take a beating this last winter? Check out our latest blog post on how to revive your lawn after a cold winter.

More Lawn Mowing FAQs

When Should I Mow A New Lawn?

Newly seeded or sodded lawns get treated exactly the same as established lawns. Wait until your new lawn reaches its optimal height, and apply the one-third rule. However, it is especially important to make sure you do not mow your new lawn before a healthy height is reached, as the new grass blades will be weaker at first and easier to damage.

Can I Mow Twice Per Week?

Mowing should typically be performed only once per week, but certain situations could require two mowings per week. If your grass is in the height of its growing season, two mowings may be required to maintain optimal height, but too much mowing can put additional stress on your lawn. Aim for once per week, and try to keep more frequent sessions to a minimum.

Can I Mow After It Rains?

Mowing can be performed after it rains, but the practice is often discouraged by lawn care professionals. Wet soil can be damaged more easily, which leads to a weaker root system for your lawn. It is also nearly impossible to get a clean cut on soaking wet grass. Waiting until your grass dries is the best way to preserve your lawn.

Does Frequent Mowing Affect Weed Growth?

Absolutely, it does! Proper and frequent mowing not only keeps your lawn looking great, it also helps choke out pesky weeds. Your turf’s optimal height is the length at which it can absorb the most sunlight and nutrition, which leads to deeper roots for your lawn. Keeping your lawn at a healthy height ensures that your grass gets the maximum amount of nourishment, and weeds will struggle to grow as a result.  

Should I Bag Grass Clippings?

Grass clippings can be bagged to avoid undesirable aesthetics, but many experts recommend leaving clippings on your lawn as a natural fertilizer. While it is true that clippings will fertilize your lawn, large clumps of clippings could actually suffocate patches of your lawn. If you choose to go bagless, consider lightly raking over clumps of trimmings to avoid damaging your lawn.

Do I Have To Sharpen My Lawn Mower’s Blades?

If you want the healthiest lawn possible, you have to sharpen and clean your lawn mower’s blades after every use. How often you should mow your lawn is irrelevant if you are mangling your turf with dull blades or spreading fungal lawn diseases every time you mow. Properly maintaining your lawn mower is crucial to your lawn’s health.

When Should I Start Mowing My Lawn?

Spring is when you will need to start cutting the grass again, with certain grass types needing a bit longer to recover after winter than others. Remember, warm-season turfs will take longer to get going due to their aversion to cold temperatures. You may want to consider letting all grass types (but especially warm grasses) grow a bit longer before the very first cut of spring. This will help your lawn with root development and grass growth as it tries to restore itself.

When Should I Stop Mowing My Lawn?

Your lawn will let you know when it is done growing for the year, but there are ways to make the transition easier on your turf. When temperatures start getting too cold for your particular grass type, set your mower height slightly lower than normal. When your lawn is almost done growing for the year and you prepare for the final cut, set the mower height even shorter. This technique will help your lawn avoid turf damage as it transitions into winter dormancy.