Warm-season · Gulf coast & Florida
St. Augustine care calendar
Broad-bladed warm-season turf that thrives in heat, humidity, and coastal soils. Sensitive to many herbicides — always check the label for St. Augustine safety.
Mowing height
3"–4" (never scalp)
N per season
2–4 lb / 1,000 sq ft
Green-up
Soil 65–70°F
Herbicide watch
Avoid MSMA, quinclorac, most 2,4-D formulations
Jan
winter
Semi-dormant (varies by zone).
- Soil testNeutral pH preferred. Iron availability drops in alkaline soil.
Feb
winter
Pre-emergent prep.
- Order pre-emergentAtrazine (labeled for St. Aug) or prodiamine. Follow local rules — atrazine restricted in some counties.
Mar
spring
Pre-emergent window.
- Apply pre-emergentSoil 2" at 55°F for 3+ days.
- First mow3"+ height. St. Augustine hates being scalped.
Apr
spring
Green-up.
- Chinch bug watchSunny, dry patches near sidewalks/driveways. Peak damage May–September.
- First N application0.5–1 lb N / 1,000 sq ft after full green-up.
May
spring
Growing.
- FeedIron-rich blend. Chelated iron for color between N apps.
- Spot-spray sedgesSedgehammer / Image labeled for St. Augustine.
Jun
summer
Peak season.
- N application0.5–1 lb N. Slow-release strongly preferred.
- Mow 3.5–4"Tall mowing shades soil, out-competes weeds.
- Watch for grey leaf spotDiamond-shaped lesions during humid stretches. Azoxystrobin if needed.
Jul
summer
Chinch bug + fungus season.
- Scout weeklyPart the canopy in yellow patches — chinch bugs look like tiny black-and-white specks.
- Water early morningReduces fungal pressure.
Aug
summer
Hold.
- Light feed0.5 lb N. Skip if grey leaf spot is active.
- Take-all root rot watchYellow patches that don't respond to N and iron — fungicide + soil pH check.
Sep
fall
Winterize prep.
- Final NBy mid-month. Late feed invites disease.
- Fall pre-emergentProdiamine or atrazine before soil drops to 70°F.
Oct
fall
Wind down.
- Potassium boost0.5–1 lb K / 1,000 sq ft.
- Stop NNo more nitrogen for the year.
Nov
fall
Slow.
- Rake leavesSt. Augustine's dense mat traps them.
Dec
winter
Rest.
- Watch for cold snapsWater lightly before hard freezes to reduce cold injury.
St. Augustine is chemically fragile. Always read the label — many common broadleaf herbicides will kill it.
Time this to your actual weather
This calendar is a great baseline. Patch shifts every task to your real soil temp, GDD, and forecast.
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