How often should you mow your lawn in San Antonio?

Weekly from March through October, then only as needed from November through February. That’s the schedule in Texas A&M AgriLife’s lawn calendars for St. Augustine and Bermuda. The rule behind it is simple: never cut off more than a third of the grass in one mow.

The one-third rule sets your schedule

Cutting off more than a third at once scalps the lawn and takes away the green leaf the grass needs to make its food. So the right schedule comes down to how fast your grass is growing, and AgriLife says that changes with temperature, rain, light and nitrogen.

Here’s how it plays out on a St. Augustine lawn. The Bexar County AgriLife office says to set the mower at 3 inches and mow before the grass reaches 4 1/2 inches. That’s why AgriLife’s calendar calls for mowing weekly through the growing season, and why it notes that in peak summer growth, some lawns need mowing twice a week.

Bermuda is cut shorter, so the margin is smaller. Common Bermuda set at 1 1/2 inches should be mowed before it reaches 2 1/4 inches, and AgriLife lists needing frequent mowing as one of Bermuda’s weaknesses. Cutting lower to stretch the time between mows backfires: AgriLife says mowing too low thins the lawn and weakens its roots.

How high to cut

Grass	Set the mower at	Mow before it reaches
St. Augustine (Raleigh, Floratam)	3 inches, up to 4 in hot summer	4 1/2 inches
Common Bermuda	1 1/2 inches	2 1/4 inches
Hybrid Bermuda	1 inch	1 1/2 inches
Zoysia (Emerald, El Toro, Jamur)	2 inches	3 inches
Buffalo grass	Looks best at 4 to 5 inches	6 inches

From the Texas A&M AgriLife Extension office in Bexar County.

When in doubt, go taller. AgriLife recommends the higher end of each grass’s range, because taller grass grows deeper roots, and it says St. Augustine in shade should be mowed taller too.

Is every other week enough?

In winter, usually yes. From November through February, AgriLife’s calendars say to mow only as needed. St. Augustine goes brown when it’s dormant for winter, and Bermuda goes dormant when the weather turns cool.

In the growing season, only if your grass grows slowly. A shady yard or a lawn in a dry spell may stay inside the one-third rule on an every-other-week schedule. But if two weeks of growth takes St. Augustine past 4 1/2 inches, you’re cutting off too much. AgriLife’s tell: if the lawn turns from green to brown after you mow, it was cut too low or not often enough.

If it already got away from you, don’t take it all down in one pass. AgriLife says to lower it gradually over several mows.

What this looks like in San Antonio

San Antonio’s weather fits that calendar. At San Antonio International Airport, the last spring freeze comes by Feb. 26 in half of years, and the first fall freeze by Nov. 28. In between, the grass is growing.

Expect two fast stretches: the wet late spring, with May the wettest month of the year, and the cooler, wetter weeks of September and October (NOAA normals). We explain the second one in why grass grows so fast in the fall. Late summer can slow things down on its own, since AgriLife calls summer dormancy a normal response to heat and drought. If every other week kept up in August, expect that to change when the fall rain comes.

Three more habits help any schedule.

Skip wet grass. If it rained on mowing day, wait for the grass to dry. AgriLife says mowing wet grass can spread disease and leaves clippings in clumps.

Leave the clippings on the lawn. They’re 2 to 4 percent nitrogen, and AgriLife says leaving them can cut the extra nitrogen your lawn needs by up to half. Keep them off the street and sidewalk, where they wash into storm drains, and blow them back into the grass.

Keep the blade sharp. A dull blade crushes and shreds the grass instead of cutting it clean.

Whether you want weekly or every other week, type your address on our site to see your mowing price.