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GUIDE · 5 MIN READ · UPDATED OCT 6, 2026
Mow St. Augustine grass at 2.5 to 4 inches. Around 3.5 inches suits most lawns, and the top of the range is best in shade or summer heat.
| Situation | Target height |
|---|---|
| Full sun | 2.5 to 3.5 in |
| Partial shade | 3.5 to 4 in |
| Summer heat or drought | 3.5 to 4 in |
| Dwarf varieties | Lower end of range |
| Before dormancy | Keep at normal height |
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The right height for St. Augustine and why
St. Augustine is a warm-season grass with wide, flat blades and thick runners called stolons. Those runners sit on top of the soil, so a low mower deck cuts straight into them. That is why St. Augustine needs a much higher cut than Bermuda or zoysia.
Keeping it between 2.5 and 4 inches protects the stolons, shades the soil, and helps the lawn resist weeds and drought. Most homeowners find 3.5 inches a good everyday height. Some dwarf varieties are bred to be kept lower, so check the variety if you know it. For a full comparison, see our chart of mowing heights for common lawn grasses.
DATA
St. Augustine grass in shade and on new sod: extension data
Shade and new sod are the two situations where St. Augustine owners most often get the height wrong. Here is what NC State Extension and Oklahoma State University Extension publish.
| Topic | What the research says |
|---|---|
| Growth habit | Warm-season grass that spreads by stolons |
| Sun and shade | Tolerates full sun to light shade |
| Mowing in shade | Keep grass in shade at a slightly higher cut |
| How much to cut | Remove no more than about a third of the leaf at once |
| When to lay sod (Oklahoma example) | At least one month before the first fall frost; plugs or sprigs at least two months before |
| First mow on new turf | Once it reaches the intended cutting height |
| Weed control on new turf | Avoid herbicides for the first 3 to 4 weeks after planting |
Oklahoma State University Extension’s shade advice matches the 3.5 to 4 inch shade height in the table above. On new sod, mowing as soon as it reaches cutting height helps the stolons spread and root. See mowing a new lawn for the first few cuts, and seed and sod costs if you are patching thin areas.
Takeaway: keep St. Augustine high, a little higher in shade, and start mowing new sod once it reaches cutting height. Or book a crew that keeps the deck set high.
Source: NC State Extension Gardener Handbook, Oklahoma State University Extension, HLA-6420, Oklahoma State University Extension, HLA-6419.
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How often to mow St. Augustine
In the main growing season, St. Augustine usually needs mowing every 5 to 7 days. Growth slows in cooler months, and mowing every two weeks or less is often enough.
Let the one-third rule guide you. At 3.5 inches, mow before it reaches about 5 inches. Waiting longer means taking off too much at once, which shocks the grass and leaves brown, stemmy patches.
St. Augustine produces a lot of clippings. Short clippings can stay on the lawn, but heavy clumps should be spread or bagged, since they can smother the runners below.
Sharp blades matter more with St. Augustine than with most grasses. The wide, coarse leaves are easy to tear, and torn tips brown and give the whole lawn a dull cast. Sharpen the blade several times a season if you mow weekly.
Time of day helps too. Mow once the morning dew has dried but before the hottest part of the afternoon, so the cut ends have time to recover before evening.
Rather not mow?
A local pro can keep St. Augustine tall, even, and on a steady schedule all season.
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Seasonal adjustments
- Spring: Wait until the lawn has greened up and is actively growing before the first full mow.
- Summer: Raise toward 4 inches. Taller blades shade the soil and reduce stress during heat and drought. See mowing in summer heat.
- Fall: Keep the normal height and mow less often as growth slows.
- Winter: In mild climates it may keep growing slowly. Mow only when needed and never drop the height.
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Common St. Augustine mowing mistakes
- Scalping: Cutting into the stolons leaves brown patches that recover slowly. Our page on a scalped lawn explains what to do next.
- Mowers that cannot go high enough: Some mowers top out near 3.5 inches. Check yours before assuming you are cutting at 4.
- Dull blades: The wide blades tear easily and turn brown at the tips.
- Mowing wet grass: Wet St. Augustine clumps heavily and can leave ruts.
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Signs St. Augustine is cut too low
- Brown or yellow patches a day or two after mowing
- Exposed runners that look like brown, cut-off ropes
- Thinning turf with weeds moving in
- Patches that stay brown for weeks instead of greening up
If you see these, raise the deck to the highest setting in range and leave it there. Our guide to measuring your mower’s actual cutting height helps you check the setting with a ruler.
Keep in mind that brown patches in St. Augustine are not always caused by mowing. Insects, disease, and drought can all look similar. If raising the height does not help within a few weeks, the cause is likely something else.
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When to call a pro
St. Augustine is less forgiving of mistakes than most lawns, and scalped areas can take a long time to fill back in. If you would rather not risk it, you can have a St. Augustine pro mow it on a regular schedule with the deck set high.
Before booking, compare lawn mowing costs. Recurring mowing is about $30 to $85 per visit for an eighth to a quarter acre, while one-time mows run about $50 to $100 (HomeGuide, 2026).
Frequently asked questions
What height should St. Augustine grass be mowed?
Mow St. Augustine grass at 2.5 to 4 inches. Around 3.5 inches suits most lawns, and the top of the range is best in shade or summer heat.
Does St. Augustine grow in shade?
Oklahoma State University Extension rates St. Augustine for full sun to light shade and recommends keeping grass in shade at a slightly higher cut. In partial shade, mow at 3.5 to 4 inches.
How often should St. Augustine be mowed?
In the main growing season, St. Augustine usually needs mowing every 5 to 7 days. At 3.5 inches, mow before it reaches about 5 inches.