Just like a good haircut, a fresh mow can instantly make your lawn look neater and more polished. But mowing regularly isn’t just about appearances: Keeping grass at the right height can also help it grow thick and healthy. And while it might be tempting to fire up the lawn mower whenever you have a free hour, the time of day can make a difference.
Mowing when the grass is wet or during the hottest part of the day can leave you with uneven cuts, clumps, or stressed grass that’s more susceptible to brown patches and other lawn problems. Choosing a better time to mow gives the grass a chance to recover—and makes the job a whole lot easier on you, too.
So, when should you head outside? We asked horticulturist and turfgrass professional Danielle Scardino, Director of Marketing and Communications at West Coast Turf, to explain the best time to mow your lawn, when to avoid mowing, and a few simple ways to keep your grass looking its best.
The Best Time of Day to Mow Your Lawn
According to Scardino, the best time to mow your lawn is generally between 8 and 10 a.m., after the morning dew has had a chance to dry but before the heat of the day sets in.
“We don't want to mow when the grass is damp or wet, because the grass blades can slip and create an unclean cut or no cut at all,” she explains.
Mid-morning also helps you avoid mowing during peak heat, when freshly cut grass can be more stressed. If the morning gets away from you, Scardino says 4 to 6 p.m. is the next-best option, once temperatures have started to cool but before evening moisture settles in.
The Worst Time of Day to Mow Your Lawn
If you can, avoid mowing when the grass is still wet, during the hottest part of the day, or late enough that the lawn won’t have much time to dry and recover before nightfall.
Early Morning
Before about 8 a.m., grass is often still damp with morning dew. Mowing wet grass can lead to clumping and uneven cuts, and it may also make fungal problems more likely. Wet clippings can clog your mower, too.
Midday
Smack-dab in the middle of the day, from 10 a.m. to 3 p.m., is one of the worst times to cut the grass. That’s because in the late morning and early afternoon, the sun is beating down on your blades. “It’s important to avoid the heat of the day when temperatures are the highest, which can lead to stress and burning,” Scardino notes. Plus, in peak heat, freshly cut blades lose their moisture fast, which can dry them out.
Late Evening
It’s also best not to leave mowing until too late in the evening, especially if dew is beginning to form. “Open cuts during dark and damp weather can leave the plant vulnerable to attack or disease,” Scardino says.
Expert Tips for Mowing Your Lawn
Nailing the timing is only half the battle. In addition to making sure you mow your lawn during the optimal two-hour window, be sure to follow these lawn-mowing tips, too.
Look to the Season
The type of grass you have will determine when and how often you need to mow. Since cool-season grasses grow quickly in spring and autumn, you’ll want to mow your lawn more frequently during these months. Warm-season grasses grow fastest from late spring through summer, so you’ll typically mow them more often during those months.
Note the Target Height
Your grass type will also help you determine how long or how short to keep your blades. Tall fescue is a cool-season grass that likes to sit between two and three inches, while Kentucky bluegrass is happiest around two-and-a-half to three-and-a-half inches. Bermuda, a warm-season grass, is cut very low, roughly a quarter to three-quarters of an inch, and St. Augustine looks best between two-and-a-half and four inches.
Follow the One-Third Rule
No matter what type of grass you have, you should never remove more than one-third of the blade at once. Cutting off too much at once can stress the grass, weaken it, and contribute to brown spots. So, for example, if the target height is three inches, let it grow to four-and-a-half inches before you mow your lawn.
Sharpen the Mower Blade
A sharp mower blade gives your grass a clean cut, which won’t just look more inviting, but will also help it recover more quickly. A dull blade, on the other hand, can tear or shred the grass, leaving behind brown tips and making it more susceptible to disease.
Check the Forecast
During periods of intense heat or drought, if your lawn is due for a mowing, raise the height slightly to help shade the soil and reduce moisture loss.
With the right timing and a few good mowing habits, you can help keep your lawn healthy and tidy all season long.
Lilly Blomquist is the associate editor at The Pioneer Woman, where she writes lifestyle stories across a wide range of topics—including news, entertainment, holidays, food, and more.
