Fertilizer Blackout Periods in South Florida — County-by-County Guide for 2025
Fertilizer Blackout Periods in South Florida — 2025 County Guide
Florida's fertilizer blackout period is the most important compliance calendar item for landscape contractors, lawn care operators, and pest and fertilization companies working in South Florida. Applying nitrogen or phosphorus fertilizers during the blackout period is a violation under local ordinance in every major South Florida county — and the fines are real.
This guide covers each county's blackout period dates, what's restricted, what you can still apply, and how fines are structured.
The Legal Basis: Florida's Fertilizer Law
Florida Statute 403.9337 establishes a model fertilizer ordinance that counties can adopt. All five South Florida counties have adopted ordinances that align with or exceed this model. Key provisions:
- Restricted nutrients: Nitrogen (N) and phosphorus (P) applications to turf and landscape plants
- Blackout period: June 1 through September 30 in most South Florida counties
- Slow-release requirement (year-round): All nitrogen applications must use fertilizer containing at least 50% slow-release nitrogen — this applies outside the blackout period too
- Buffer zones: No fertilizer containing nitrogen or phosphorus within 3 feet of any water body edge; phosphorus-free formulations only within 10 feet
County-by-County Blackout Period Reference 2025
South Florida Fertilizer Blackout Periods by County 2025
| County / Municipality | Blackout Period | Restricted Nutrients | Starting Fine |
|---|---|---|---|
| Miami-Dade County | June 1 – Sept 30 | Nitrogen, Phosphorus | $250 first offense |
| Broward County | June 1 – Sept 30 | Nitrogen, Phosphorus | $250 first offense |
| City of Fort Lauderdale | June 1 – Sept 30 | Nitrogen, Phosphorus | $500 first offense |
| Palm Beach County | June 1 – Sept 30 | Nitrogen, Phosphorus | $200 first offense |
| Boca Raton | June 1 – Sept 30 | Nitrogen, Phosphorus | $500 first offense |
| Collier County | June 1 – Sept 30 | Nitrogen, Phosphorus | $200 first offense |
| Monroe County | June 1 – Sept 30 | Nitrogen, Phosphorus | $250 first offense |
Fines escalate significantly for repeat violations — second offense typically $500–$1,000; third and subsequent $1,000–$2,500 or more depending on municipality. Licensed contractor violations may also trigger license complaints. Verify current ordinance with each county/municipality — ordinances are subject to amendment. Source: County ordinances; FloridaLandscapeIQ, 2025.
What You CAN Apply During the Blackout Period
The blackout restricts nitrogen (N) and phosphorus (P) — it does not restrict all fertilization. Lawns and landscape plants still have nutritional needs during the summer months, and several applications are permitted:
Iron (Fe): Chelated iron or iron sulfate applications are permitted year-round. This is the most important allowable treatment during blackout — South Florida's alkaline, sandy soils produce iron deficiency (interveinal chlorosis) that iron supplements directly address without the water quality risk of nitrogen or phosphorus.
Potassium (K): Potassium is not restricted during blackout. Potassium sulfate and potassium chloride applications help turf maintain cell turgor and disease resistance during the stress of summer heat.
Magnesium (Mg): Magnesium sulfate (Epsom salts) or granular magnesium supplements are permitted. South Florida's leached soils are frequently magnesium-deficient.
Micronutrients: Zinc, manganese, and boron applications are not subject to blackout restrictions.
Slow-release nitrogen fertilizers that meet the organic definition: Some organic nitrogen sources (feather meal, soybean meal, blood meal) may fall outside the blackout restriction depending on their nitrogen release rate — verify the specific ordinance and product label.
Contractor Compliance Best Practices
Train every crew. The contractor is liable for applications made by unlicensed crew members. Florida requires a licensed Pest Control Operator or Fertilizer Applicator for commercial-scale lawn fertilization — ensure the license covers all activities.
Keep application records. Date, location, product, application rate, and applicator name should be logged for every job. Records protect against false complaints and demonstrate compliance pattern if a violation notice is issued.
Use products with clear labels. Products labeled "0-0-K" (no nitrogen, no phosphorus, potassium only) or "Iron supplement" are unambiguous during blackout. Avoid multi-nutrient products that require reading the guaranteed analysis to confirm N and P content.
Schedule pre-blackout applications correctly. A May 31 application of slow-release nitrogen allows some continued nitrogen availability into the blackout period without violating the ordinance — but only if applied before June 1. Time the final spring application accordingly.
Find licensed pest control and fertilization contractors throughout South Florida through the FloridaLandscapeIQ Contractor Directory.
Source: Florida Fertilizer Law (FL Statute 403.9337); Miami-Dade, Broward, Palm Beach, Collier, Monroe county fertilizer ordinances; UF/IFAS Florida Lawn Handbook; FloridaLandscapeIQ Staff, April 2025.