Floratam St. Augustine Fertilization: Diagnose Thin Areas Before Feeding

Thin Floratam areas in Port St. Lucie need diagnosis (pests, disease, irrigation, buried debris) before fertilization. "Turf builder" fertilizer with slow-release N, low P, applied at 70°F+ consistent temps, within local regulations.

Diagnose Thin Spots First

• Chinch bugs: Yellowing edges; check thatch with coffee can flush.
• Take-all root rot: Roots short, black; patchy decline.
• Gray leaf spot: Oblong lesions; humid conditions.
• Irrigation issues: Dry spots (poor coverage) or wet spots (leaks).
• Buried construction debris: Common in new developments; dig test holes.

Fertilization Guidelines for Floratam (S. FL)

• Timing: When night temps consistently >70°F (typically March–Oct).
• Analysis: 16-0-8, 15-0-15, or similar (low/zero P per FL law).
• Slow-release N: 50%+ (SCU, PCU, methylene urea).
• Rate: 0.5–0.75 lb N/1,000 sq ft per application.
• Frequency: 4–6x/year max (check county ordinance).
• Image (atrazine) limit: 2 apps/year max; not >85°F.

Local Regulations (St. Lucie County)

• Fertilizer blackout: June 1–Sept 30 (no N/P).
• Zero phosphorus unless soil test deficiency.
• 50% slow-release N minimum.
• Deflector shields near water.

Action Plan

1. Soil test thin vs. thick areas separately.
2. Chinch bug test (coffee can flush) in thin areas.
3. Irrigation audit (catch cans).
4. Dig 6" holes in thin spots—check for debris, root depth.
5. Fix identified issues FIRST.
6. Then fertilize per above guidelines.

Thickening Floratam requires fixing the cause of thinning, not just adding fertilizer. Diagnose, correct, then feed appropriately within regulations.