Warm-season grass

St. Augustine Grass Lawn Care Schedule

St. Augustine is a warm-season grass with broad, coarse blades that handles shade and coastal salt better than other Southern turfs. It is not cold-hardy, so it's grown in the warmest zones, where it makes a thick, blue-green lawn that spreads by above-ground runners.

Type: Warm-season
Mowing height: 3–4″
Nitrogen budget: 2–4 lbs N / 1,000 sq ft / yr
Growth habit: Spreading (self-repairs)
Shade tolerance: High
Drought tolerance: Moderate
Traffic tolerance: Low
USDA zones: 8–10

Get region-specific timing

Pick your USDA hardiness zone for a St. Augustine schedule with timing shifted to your local season:

Key care windows

Timing windows are flexible (early / mid / late) and tuned to a typical transition-zone season — soil temperature and your local weather should always have the final say.

mid-February to mid-March

Spring pre-emergent (crabgrass)

Apply a pre-emergent herbicide as soil temperatures approach 55°F to stop crabgrass and other summer weeds before they germinate. A second application 6–8 weeks later extends control through the season.

Don't apply a pre-emergent if you plan to seed — it blocks grass seed too. Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.

mid-February to late March

Spring green-up & first mow

As soil temperatures reach about 55°F the lawn breaks dormancy and greens up. Once it's about half green, mow low to clear dormant material and let sunlight reach the crowns. Don't fertilize until it's at least 80% green.

late April to mid-May

First feeding

Make the first fertilizer application 2–4 weeks after full green-up, once the lawn is actively growing. Feed about 2–4 lbs of nitrogen per 1,000 sq ft per year across the warm months. An iron supplement deepens color without forcing the excess top growth that heavy nitrogen would.

Several weed killers that are fine on other lawns will damage St. Augustine — confirm the label lists it by name before spraying. Keep nitrogen at or below ~1 lb per 1,000 sq ft per feeding. Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.

early May to late June

Aeration & dethatching

Core-aerate (and dethatch if the thatch layer is over about ½") during the peak growing season, when warm-season turf recovers fastest. Avoid aerating dormant or drought-stressed turf.

early June to late August

Summer feeding program

Summer is the warm-season growth peak. Feed about 2–4 lbs of nitrogen per 1,000 sq ft per year across the warm months. An iron supplement deepens color without forcing the excess top growth that heavy nitrogen would. Spread the annual budget across the season rather than applying it all at once.

Never exceed ~1 lb of nitrogen per 1,000 sq ft in a single feeding. Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.

early June to late August

Summer weed & pest watch

Spot-treat broadleaf weeds during active growth, never on drought-stressed turf. Watch for insect and disease pressure in hot, humid weather and treat problem areas rather than the whole lawn.

early September to late September

Final feeding & soil test

Give a final feeding in early fall, then stop nitrogen — late-season nitrogen pushes tender growth into frost. Fall is also the best time to take a soil test so amendments are ready before spring.

Stop nitrogen about 6 weeks before your first expected frost. Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.

late September to mid-October

Fall pre-emergent (winter weeds)

A fall pre-emergent applied before soil cools below about 70°F controls winter annual weeds like Poa annua and henbit.

Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.

early November to late December

Winter dormancy

Expect a brown, dormant lawn from first frost until spring green-up. Hold off on fertilizer and pre-emergent. A light watering during extended winter drought helps prevent desiccation.

Month-by-month schedule

A quick at-a-glance plan for St. Augustine grass, month by month.

Month	Season	What to do
January	Winter· dormant	Dormant season — no feeding; water lightly only during extended drought.
February	Winter	Watch for green-up; do the first low mow to clear winter material. Apply crabgrass pre-emergent before soil reaches ~55°F.
March	Spring	Watch for green-up; do the first low mow to clear winter material. Apply crabgrass pre-emergent before soil reaches ~55°F.
April	Spring	Make the first feeding once the lawn is fully green and growing. Mow at 3–4" and water deeply as needed.
May	Spring	Make the first feeding once the lawn is fully green and growing. Core-aerate during peak growth; dethatch if thatch is heavy. Mow at 3–4" and water deeply as needed.
June	Summer	Core-aerate during peak growth; dethatch if thatch is heavy. Continue the summer feeding program on schedule. Spot-treat weeds and scout for pests; water deeply in heat. Mow at 3–4" and water deeply as needed.
July	Summer	Continue the summer feeding program on schedule. Spot-treat weeds and scout for pests; water deeply in heat. Mow at 3–4" and water deeply as needed.
August	Summer	Continue the summer feeding program on schedule. Spot-treat weeds and scout for pests; water deeply in heat. Mow at 3–4" and water deeply as needed.
September	Fall	Apply a fall pre-emergent for winter weeds before soil cools. Make the final feeding of the year; take a soil test. Mow at 3–4" and water deeply as needed.
October	Fall	Apply a fall pre-emergent for winter weeds before soil cools. Mow at 3–4" and water deeply as needed.
November	Fall· dormant	Lawn is dormant — no feeding; water lightly only in extended drought.
December	Winter· dormant	Lawn is dormant — no feeding; water lightly only in extended drought.

St. Augustine care guide

Mowing

Mow St. Augustine tall — 3–4". Mowing too low scalps it and invites weeds and disease. Keep the mower blade sharp to avoid shredding its wide blades.

Watering

St. Augustine prefers about 1" of water per week and is less drought tolerant than bermuda or zoysia. Water deeply in the early morning; chronic wet conditions encourage fungal disease.

Fertilizing

Feed about 2–4 lbs of nitrogen per 1,000 sq ft per year across the warm months. An iron supplement deepens color without forcing the excess top growth that heavy nitrogen would.

Weed control

Use a pre-emergent in spring and fall, and choose broadleaf products labeled as safe for St. Augustine — some common herbicides will injure it. Watch for chinch bugs in hot, dry spots, which can mimic drought damage.

Strengths

Best shade tolerance of the warm-season grasses
Thrives in heat, humidity, and coastal conditions
Spreads quickly by stolons to fill in

Watch out for

Not cold-hardy — limited to the warmest zones
Prone to chinch bugs and gray leaf spot
Coarse texture; doesn't take heavy traffic

Safety first

Several weed killers that are fine on other lawns will damage St. Augustine — confirm the label lists it by name before spraying. Keep nitrogen at or below ~1 lb per 1,000 sq ft per feeding.