St. Augustine Care Calendar

Month-by-month care schedule for St. Augustine grass lawns. Mowing, fertilizer, chinch bug monitoring, and disease prevention — timed to your season.

Mowing
3.5-4"
Annual N
2-6 lb N/1K sqft (varies by region)
Water
1-1.5 inches/week
pH
6.0-6.5
10
What to do now

October

Dormant
Reduce mowing to every 10-14 days
MowingMed
Watch for large patch (brown patch) — circular patches of brown grass
DiseaseHigh
Leaf removal — don't let debris smother stolons
GeneralMed

Large patch (Rhizoctonia) activates in fall when temps drop below 80°F. Look for circular brown areas with a yellow/orange border. Preventive fungicide (azoxystrobin) if history of disease.

See the full St. Augustine pre-emergent application timing guide

Full Year Calendar

Every task, every month. Tap a month to see what's on the schedule.

January

Dormant
Monitor for winter weeds (Poa annua, henbit, chickweed)
Keep mower blades sharp for clean cuts
Avoid foot traffic on frost-stressed turf

St. Augustine may stay green in Zone 9b-10 but grows very slowly. Do NOT fertilize — nitrogen pushes weak growth before the grass can use it.

February

Active
Apply pre-emergent for crabgrass when soil approaches 55°F!
Apply pre-emergent for broadleaf/sedge at 65°F soil temp!
DO NOT scalp — maintain at 3.5-4" year-round!

St. Augustine has TWO pre-emergent windows: crabgrass at 55°F and broadleaf weeds/sedge at 65°F. Do NOT scalp St. Augustine like you would bermuda.

March

Active
First nitrogen application (0.5 lb N/1K sqft) once actively growing!
Resume mowing at 3.5-4" every 7-10 days!
Spot-treat broadleaf weeds with Celsius WG per label, NOT 2,4-D

CAUTION: 2,4-D can damage St. Augustine, especially during green-up and in hot weather. Use Celsius WG per label instead — it is labeled for St. Augustine including Floratam. Do NOT reach for atrazine: Floratam is not tolerant of atrazine (Texas A&M EHT-144).

April

Active
Mow every 5-7 days at 3.5-4"!
Second nitrogen application (0.5-1 lb N/1K sqft)!
Begin chinch bug scouting in sunny areas
Apply preventive grub control (imidacloprid)

Chinch bugs are the #1 St. Augustine pest. Scout sunny, drought-stressed areas first — that's where they start. Use the float test: cut both ends off a coffee can, push into soil, fill with water, watch for small black-and-white insects.

May

Active
Mow every 5-7 days at 3.5-4"!
Begin deep watering schedule (1-1.5" per week)!
Treat nutsedge with Sedgehammer or sulfentrazone
Plug or sod bare spots — warm soil ensures fast establishment

Active growth season. St. Augustine fills gaps via stolons (above-ground runners). This is the best time for repair work with plugs or sod.

June

Active
Maintain mowing at 3.5-4" every 5-7 days!
Water deeply 2-3 times per week (early morning only)!
Peak chinch bug season — scout weekly in sunny areas!
Apply iron supplement for color without excessive growth

Peak chinch bug pressure June-August. Yellowing patches in sunny areas that don't respond to watering are likely chinch bug damage, not drought. Treat with bifenthrin.

July

Active
Continue mowing at 3.5-4"!
Light nitrogen or iron-only application for color
Watch for gray leaf spot (diamond-shaped lesions on blades)!
Deep, infrequent watering!

Gray leaf spot peaks in hot, humid weather. Avoid nitrogen during active gray leaf spot — it feeds the fungus. Use iron for color instead.

August

Active
Continue summer mowing routine!
Apply fall pre-emergent for winter weeds!
Scout for sod webworms (ragged-edged blades, moths at dusk)

Fall pre-emergent prevents Poa annua and winter broadleaves. Apply 2-3 weeks before soil temps drop below 70°F.

September

Active
Apply potassium (0-0-50 or 0-0-62) for winter hardiness!
Final nitrogen application of the season
Reduce mowing frequency as growth slows

Potassium strengthens cell walls for winter. Stop nitrogen after this month — late nitrogen promotes disease-prone growth going into dormancy.

October

Dormant
Reduce mowing to every 10-14 days
Watch for large patch (brown patch) — circular patches of brown grass!
Leaf removal — don't let debris smother stolons

Large patch (Rhizoctonia) activates in fall when temps drop below 80°F. Look for circular brown areas with a yellow/orange border. Preventive fungicide (azoxystrobin) if history of disease.

November

Dormant
Clear leaves and debris
Monitor for winter weeds — spot-treat if needed

St. Augustine slows significantly. Minimize traffic on the lawn. Do not fertilize.

December

Dormant
Equipment maintenance and blade sharpening
Soil test and plan spring fertilizer program

Off-season planning. Soil test results take 2-3 weeks — send now to have data before spring green-up.

Quick Reference

Mowing Height

3.5-4"

Dormant below 55°F soil temp. Green-up at 65°F.

Watering

2-3 times per week during active growth, reduce in cooler months

0.5-0.75 inches per session (1-1.5 inches total per week) per session. St. Augustine has shallow roots and needs more consistent moisture than bermuda. Sandy Florida soils may need up to 2 inches per week. Water early morning only to reduce disease pressure.

Fertilizer Program

2-6 lb N/1K sqft (varies by region)/year

Soil pH target: 6.0-6.5

Pests & Weeds to Watch

Chinch BugsNutsedgeCrabgrassDoveweedSod WebwormsMole CricketsWhite GrubsArmywormsDollarweedPoa annua

Want the full St. Augustine guide?

Read the complete St. Augustine care guide — quick facts, mowing heights, safe products, and the agronomy behind every recommendation.

Read the St. Augustine care guide

Want to compare all warm-season grasses side by side?

See the full Warm Season Calendar
Read the full St. Augustine grass guide →

Frequently Asked Questions

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St. Augustine in other climate zones

The calendar above is for the south (USDA zones 9 and warmer). St. Augustine is also grown in the zone below, and the timing is genuinely different — soil temperature in the transition zone runs three to five weeks behind the south, which moves pre-emergent, fertilizer and aeration with it. Find your zone and work from that table.

Growth status and soil temperature are derived from each zone's soil curve together with St. Augustine's own dormancy and green-up thresholds, so they describe that zone rather than an average of all of them.

St. Augustine in the Transition zone — USDA 7 to 8

The band from the Carolinas across to Oklahoma and up through the lower Midwest, where both warm- and cool-season grasses are grown and neither is entirely comfortable. Timing here runs three to five weeks behind the south.

Month-by-month St. Augustine lawn care schedule for the transition zone
MonthGrowthMowWhat to doWhat you can skip
Januarydormant
~35°F soil, cooling
Not this month — the lawn is dormant.
  • Keep leaves off the dormant lawn
  • Service the mower
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Februarydormant
~36°F soil, steady
Not this month — the lawn is dormant.
  • Soil test
  • Keep leaves off the dormant lawn
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Marchdormant
~44°F soil, warming
Not this month — the lawn is dormant.
  • Spring pre-emergent, before the soil hits 55 F — per label for your grass and your square footage — these products are sold on season-long residual, and the label rate is what buys it — don't spray above 90°F
  • Keep leaves off the dormant lawn
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Aprildormant
~54°F soil, warming
Not this month — the lawn is dormant.Nothing this month.
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
  • Everything, honestly. There is no useful lawn work this month.
Maywaking up
~64°F soil, warming
2.5–3"
every 7-10 days
  • First mow of the season
  • Mow on a routine
  • Spot-treat broadleaf weeds — sensitive grass — don't spray above 85°F
  • Fertilizer until the lawn is fully green — roughly 75% green-up, not the first hint of color.
Juneactive growth
~74°F soil, warming
2.5–3"
every 5-7 days
  • Mow on a routine
  • Mid-season nitrogen — 0.5-1 lb N per 1,000 sq ft
  • Core aerate
  • Preventive grub control
  • Scout for chinch bugs
—
Julypeak growth
~80°F soil, warming
2.5–3"
every 5-7 days
  • Mow on a routine
  • Iron for color instead of more nitrogen
  • Core aerate
  • Scout for chinch bugs
—
Augustpeak growth
~80°F soil, steady
2.5–3"
every 5-7 days
  • Mow on a routine
  • Last nitrogen of the year — 0.5 lb N per 1,000 sq ft
  • Scout for chinch bugs
—
Septemberslowing
~72°F soil, cooling
2.5–3"
every 7-10 days
  • Mow on a routine
  • Potassium for winter hardiness — only if a soil test says your soil is short of it — 1 lb K2O per 1,000 sq ft — 1.6 lb of 0-0-60, or 2 lb of 0-0-50
  • Fall pre-emergent for winter weeds — per label for your grass and your square footage; if you are planning a second application, the label's ANNUAL maximum is the number that governs — don't spray above 90°F
  • Spot-treat broadleaf weeds — sensitive grass — don't spray above 85°F
  • Preventive fungicide for large patch
  • Nitrogen — you are inside six weeks of first frost in most of this zone. Late nitrogen pushes soft growth that freeze damage takes first.
  • Aeration — the growing season left is too short to close the holes before dormancy.
  • Seeding or sodding — a warm-season lawn established now has no time to root before winter.
Octobergoing dormant
~60°F soil, cooling
2.5–3"
every 7-10 days
  • Last mow before dormancy
  • Nitrogen — too late in the year. Late nitrogen pushes soft growth that freeze damage takes first.
  • Aeration — there is not enough growing season left to close the holes.
Novemberdormant
~46°F soil, cooling
Not this month — the lawn is dormant.
  • Keep leaves off the dormant lawn
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.
Decemberdormant
~38°F soil, cooling
Not this month — the lawn is dormant.
  • Keep leaves off the dormant lawn
  • Service the mower
  • Mowing — a dormant lawn is not growing. Nothing to cut.
  • Fertilizer — dormant turf cannot take up nitrogen. It feeds winter weeds instead.
  • Regular irrigation — water only to stop crowns drying out in a long dry spell.