Nitrogen and phosphorus fertilizers cannot be applied to lawns or landscape plants anywhere in Miami-Dade County until Oct. 31, a restriction that covers homeowners, condo associations and landscapers in Aventura, Sunny Isles Beach and Golden Beach.
The Miami-Dade County Department of Regulatory and Economic Resources posted a reminder on Monday, Aug. 3, urging residents to skip those fertilizers during the wet months to reduce pollution flowing into Biscayne Bay.
Why the county banned fertilizer during rainy season
Fertilizer applied during South Florida's intense rainy season washes through storm drains and canals into surface waters before plants can absorb it, according to a county news release. That runoff has contributed to seagrass die-offs, algal blooms and fish kills in Biscayne Bay.
A 2023 Biscayne Bay Economic Study pegged the combined economic impact of bay-related activities at $64 billion.
What the fertilizer ordinance requires
The ban runs each year from May 15 through Oct. 31 under Ordinance No. 21-26, enacted by the Board of County Commissioners on April 20, 2021. Co-prime sponsors were Commissioners Eileen Higgins and Rebeca Sosa. The ordinance is stricter than Florida's state model, with larger fertilizer-free zones near water bodies and tighter nitrogen limits.
During the restricted period, no one may apply fertilizers containing nitrogen or phosphorus to turf or landscape plants. The rule covers residential homeowners, commercial landscape companies, property managers and institutional applicators such as schools, parks and businesses.
Year-round, additional limits apply:
- No fertilizer within 20 feet of any water body, canal, wetland or storm drain.
- No more than 4 pounds of nitrogen per 1,000 square feet per calendar year.
- Granular fertilizers must contain at least 65% slow-release nitrogen.
- Phosphorus is banned year-round unless a soil test confirms a deficiency.
- No nitrogen application during any National Weather Service flood watch, tropical storm watch, or when 2 inches or more of rain in 24 hours is forecast.
Who's exempt from the fertilizer restrictions
Vegetable and community gardens, yard waste compost and mulch, and tree trunk injections by a certified arborist are exempt. Golf courses and athletic fields follow separate specialized turf management rules.
How the ban is enforced and penalized
In incorporated municipalities like Aventura, Sunny Isles Beach and Golden Beach, local code enforcement handles violations. The county can step in if a municipality does not enforce the ordinance. Violations carry civil penalties under Chapter 8CC of the county code.
What happens when the ban lifts Oct. 31
The ban lifts Oct. 31. After that date, nitrogen and phosphorus fertilizers may be applied again subject to the year-round limits on rates, slow-release requirements, the 20-foot setback from water, and weather restrictions. Residents can find full compliance details at miamidade.gov/fertilizer.
