Most homeowners have the same summer lawn-care routine: mow once a week and call it good. But lawn experts say mowing on a fixed weekly schedule isn’t always the healthiest approach for your lawn.
If you’re wondering how often you should mow your lawn during summer, the answer isn’t every seven days—or even every two weeks. In fact, experts say you shouldn’t be following a mowing schedule at all.
Instead, the key to a greener, healthier lawn is following what’s known as the 1/3 rule.
Why You Shouldn’t Mow Your Lawn on a Set Schedule
The problem with mowing on the same day every week is that grass doesn’t grow at the same rate all summer long.
A rainy stretch can trigger rapid growth, while extreme heat and drought can slow it to a crawl. Depending on weather conditions, your lawn may need mowing twice in one week—or go much longer between cuts during hot, dry weather.
That’s why experts recommend paying attention to grass height rather than the calendar.
The 1/3 Rule Explained
The 1/3 rule is simple: Never remove more than one-third of the grass blade’s height during a single mowing.
If your grass is 4½ inches tall, for example, you shouldn’t cut off more than 1½ inches. If it’s 3 inches tall, remove no more than 1 inch.
The 1/3 rule isn’t some obscure landscaping trick, either. It’s one of the most widely recommended lawn-care practices in the country and appears in Cooperative Extension guides from universities across the United States.
Following this rule helps prevent stress and keeps grass healthy during the hottest months of the year.
Know Your Grass’s Ideal Height
Different turf types thrive at different heights. Here’s a breakdown by type.
Proper Lawn-Mowing Height for Cool-Season Grasses
- Kentucky bluegrass: 2 to 3 inches
- perennial ryegrass: 2 to 3 inches
- tall fescue: 3 to 4 inches
Proper Lawn-Mowing Height for Warm-Season Grasses
- Bermudagrass: ½ to 2 inches
- St. Augustine grass: 3 to 4 inches
- Zoysiagrass: ¾ to 2 inches
What Happens If Your Lawn Gets Too Tall?
If your grass is taller than its recommended height, cutting it back to the proper height can stress the lawn.
Grass blades act as the plant’s food factory, converting sunlight into energy. When too much of the blade is removed at once, the grass becomes stressed and has fewer resources to support healthy root growth and recover from summer heat. The result can be a weaker lawn that’s more susceptible to drought, weeds, pests, and disease.
If your grass has gotten too tall (we all go on vacation, right?), start by removing one-third of the height. After three to four days, or once you’ve seen the grass recover from its last trim, mow the lawn again. Repeat until the lawn reaches the proper height for its variety.
A Taller Lawn Is Usually Better in Summer
Experts generally suggest keeping lawns on the higher end of their recommended height range during the summer months. Longer grass helps shade the soil, retain moisture, and protect roots from extreme temperatures. It can also make it harder for weeds to take hold.
The healthiest lawns aren’t maintained by the calendar—they’re maintained by grass height. Instead of mowing every Saturday out of habit, watch your lawn’s growth and follow the 1/3 rule. You'll put less stress on your grass and end up with a greener, more resilient lawn all summer long.
