Quick Answer: St. Augustine grass should be mowed to a height of 3 to 4 inches, which is taller than most other lawn grasses. In the New Orleans heat, keeping it on the higher end, around 3.5 to 4 inches, helps it shade its roots, hold moisture, and crowd out weeds. Never cut it below 2.5 inches, and never remove more than one-third of the blade in a single mowing. Cutting St. Augustine too short scalps it and invites browning, weeds, and disease. TurnKey Lawn Care sets the right height every visit.
Detailed Explanation
St. Augustine is the most common lawn grass in New Orleans, and it has a clear preference: it likes to be cut tall. Unlike Bermuda, which can be kept low, St. Augustine grows by spreading runners across the surface and depends on its broad leaf blades to feed itself. When you keep it at 3 to 4 inches, those tall blades shade the soil, keep the roots cool, lock in moisture, and block sunlight from reaching weed seeds.
The right height changes slightly with the season. During the peak heat of a New Orleans summer, the higher end of the range, 3.5 to 4 inches, protects the lawn from drying out and scorching. In spring and fall, when temperatures are milder, you can mow toward the lower end of 3 inches without stress. The key is to never scalp it, because St. Augustine recovers slowly from being cut too short.
Mowing frequency works hand in hand with height. Following the one-third rule means you cut before the grass gets too tall, so each mow is light and stays within the target range. During the fast-growing summer, that usually means weekly mowing. Our parent guide on lawn maintenance and mowing and our St. Augustine grass care guide go deeper on keeping this grass thick and healthy.
Important Considerations
Cutting St. Augustine too short causes real damage. Scalping exposes the runners and soil, which stresses the plant, browns the lawn, and opens bare spots where weeds move in. Because St. Augustine spreads by surface runners rather than deep roots, a scalped lawn can take weeks to recover and may thin out permanently in shaded areas. Our answer on what happens if you cut grass too short explains the full chain of damage.
Shade tolerance is a St. Augustine strength, and height supports it. In the partly shaded yards common under New Orleans live oaks, keeping the grass at the taller end of the range gives it more leaf surface to gather the limited light. Mowing shaded St. Augustine too low almost guarantees thinning and bare patches.
Blade sharpness matters as much as height for this grass. St. Augustine has wide, coarse blades that show a ragged cut clearly. A dull mower tears the tips, leaving a frayed, whitish look across the lawn and inviting disease in our humid air. Sharp blades and the right height together keep the lawn looking clean and staying healthy.
What to Do Next
Getting St. Augustine height right takes attention to season, shade, and growth rate, plus sharp equipment. TurnKey Lawn Care knows this grass and the New Orleans climate, and we set the mower to the height that keeps your lawn thick, green, and weed-resistant all season.
Call TurnKey Lawn Care at (504) 386-5468 for a free estimate. We are your friendly neighborhood lawn care partner across the New Orleans metro, and every visit comes with our satisfaction guarantee and no hidden charges.