Complete St. Augustine Lawn Care Guide for Southern California

Watering

Deep and infrequent. Saturate root zone (6–8 inches), then wait until top 2–3 inches dry. No fixed schedule—adjust for temp, wind, rain. Typically 1–2x/week summer, less winter.

Mowing Height

2.5–3 inches minimum. Taller = more photosynthesis, deeper roots, better weed suppression. Semi-dwarf varieties: 1.5–2 inches.

Diseases & Pests

• SAD (St. Augustine Decline): Virus. Use resistant cultivars (Floratam, Palmetto).
• Brown patch, gray leaf spot: Fungal. Proper water/fertility prevents most.
• Chinch bugs: Suck sap, cause yellow patches. Flotation test for ID.
• Grubs, fire ants: Treat only if thresholds exceeded.

Diagnose via lab sample (UC Davis, local extension) before treating.

Weed Control

• Broadleaf: 2,4-D + dicamba + mecoprop (Trimec) or atrazine (St. Augustine safe).
• Grassy: Monument, Manor, Blade (professional).
• Best: Hand removal + dense turf.

Fertilization Schedule

• Early spring: Higher phosphorus (e.g., 16-20-0) for root growth.
• Summer: Higher nitrogen (e.g., 21-0-0 or 24-0-11).
• Fall: Higher potassium (e.g., 10-0-20) for winter hardiness.

Rate: 1 lb N/1,000 sq ft per active month. Example: 20-0-10 at 5 lbs = 1 lb N.

Dethatching

If thatch >½ inch: vertical mow (3-inch blade spacing) during active growth. Remove debris, mow, water, apply 1 lb N/1,000 sq ft to recover.

Faster Fill-In

Proper water, fertility, mowing, pest control. Low mow (2 inches) spring encourages runners. But never scalp.

Dog Urine Spots

Dilute immediately with water. Or train dog to mulch area. No magic product—nitrogen burn is physical.