The short answer
Keep St. Augustine grass between 3.5 and 4 inches tall. That is taller than most people think, and it is the single biggest thing you can do for a healthy lawn in Hernando County.
St. Augustine mowing height by variety
| Variety | Mowing height |
|---|---|
| Floratam, BitterBlue, Classic | 3.5 to 4 inches |
| Palmetto, Raleigh | 3 to 4 inches |
| CitraBlue | 2 to 3 inches |
| Seville and other dwarf types | 2 to 2.5 inches |
Most Spring Hill lawns are Floratam, so 3.5 to 4 inches is the number to remember. UF/IFAS says to mow at the highest recommended height for your variety.
Why taller is better here
St. Augustine has wide blades and shallow roots. Tall grass shades its own roots, holds moisture through a hot afternoon, and crowds out weeds. Scalp it down to 2 inches and the sun hits the soil, the roots cook, and dollarweed and crabgrass move in within weeks.
The one-third rule
Never cut off more than a third of the blade in one mow. If the lawn got away from you after a rainy week, take it down in two passes a few days apart instead of one hard cut.
How tall should St. Augustine get before you mow?
Use the one-third rule backward. If you keep it at 4 inches, mow before it passes about 6 inches. In the rainy season that usually means every 5 to 7 days.
Can you scalp St. Augustine grass?
No. Scalping cuts into the runners (stolons) that hold St. Augustine together, and bare runners burn in the Florida sun. A scalped lawn goes brown in patches, and weeds fill the gaps. If it already happened, raise the mower back to 3.5 to 4 inches, water on your normal schedule, and give it a few weeks. Patches that stay brown usually need new sod.
Mower blade matters
A dull blade tears the grass instead of cutting it, and the torn tips turn brown. Sharpen or replace the blade every 20 to 25 hours of mowing. Our crews swap blades weekly in summer.
Summer versus winter
From May through October, mow weekly at 4 inches. From November through March, growth slows and every two weeks at 3.5 inches is plenty. Bahia grass, common on larger Brooksville lots, likes the same 3.5 to 4 inch range. Dwarf St. Augustine, such as Seville, Captiva, and Delmar, is the exception: UF/IFAS says to keep it at 2 to 2.5 inches. Picking a grass for a new lawn? See St. Augustine vs Bahia vs zoysia.
Want it handled?
Supreme Landscape does lawn mowing in Spring Hill, Weeki Wachee, and Brooksville at the right height on a set schedule, $35 to $40 per cut for most yards. If scalping already killed patches, we fix them with new sod. Call or text 727-809-8150 for a free quote.
Source: UF/IFAS Extension: St. Augustinegrass for Florida Lawns
