Help Curb Red Tide and Keep Water Clean by Following Fertilizer Rules

From June 1 through Sept. 30, it is against the law to use fertilizer that contains nitrogen and/or phosphorus. Hillsborough County's rules on the use of fertilizers containing these nutrients are intended to protect and preserve the cleanliness of local streams, rivers, lakes, and bays. Protecting the county's water reduces the chances of severe algae blooms, such as red tide, from forming. This, in turn, benefits the health of the area's wildlife and residents.

Nitrogen and phosphorous-based fertilizer and red tide

The issues caused by nitrogen and phosphorus-based fertilizers may worsen during summer months when West-Central Florida receives much of its rainfall. It's during this season that deluges of fertilizer-rich water can enter the county's waterways through stormwater and irrigation runoff. This is especially problematic where there are no shoreline plants to consume nutrients.

Excessive algae growth, sometimes in the form of red tide, can occur when certain types of fertilizer mixes with bodies of water. The resulting algae blooms in the water can block sunlight needed for seagrass and other desirable aquatic plants to grow. When aquatic plant growth is reduced, oxygen levels decrease. Lower oxygen levels as well as toxins contained in some algae can cause fish kills.

Large and out-of-control algae blooms can also be harmful to other aquatic animals, including manatees and dolphins. For instance, the neurotoxin produced by red tide can cause manatees to have seizure-like symptoms when inhaled. In severe cases, the animals drown as a result. Furthermore, red tide can induce coughing and sneezing in dolphins, which is similar to the irritation it causes in humans.

Fertilizer ordinance details

The fertilizer ordinance applies to residents, homeowners, HOA common property management, businesses, governmental entities, and companies that apply fertilizer and provide landscape services to non-agricultural property.

Here are some key provisions of Hillsborough County's fertilizer ordinance:

• Fertilizers containing nitrogen and phosphorous may not be applied on turfgrass or landscape plants from June 1 through Sept. 30, though the ordinance does not prohibit stores from selling the material during this application blackout
• Fertilizers containing phosphorous may not be placed on turfgrass or landscape plants at any time unless a soil analysis showing a phosphorous deficiency has been performed by a qualified laboratory
• Fertilizers containing nitrogen must be at least 50 percent controlled or slow-release
• Fertilizer may not be applied, spilled, or deposited on any impervious surface. If fertilizer does land on these surfaces, it must be removed and may not be washed, swept, or blown into storm drains, ditches, or water bodies
• Fertilizers containing nitrogen or phosphorous may not be applied when it is raining, within 36 hours of a predicted rainfall of at least 2 inches, during a flood watch or warning, or when a tropical storm or hurricane looms
• Fertilizer may not be spread within 10 feet of any surface water or water body
• Violation of any of the ordinance's provisions is a misdemeanor and can result in a fine of up to $500 and/or up to 60 days in jail

Enforcement and violation reporting

The fertilizer ordinance is enforced by Hillsborough County Code Enforcement. Suspected ordinance violations can be reported online.

Further information

More information can be found on the Fertilizer Ordinance and Regulation webpage.

Contact Hillsborough County Extension Service for more information at (813) 744-5519.

NOTE: Mention of a commercial product does not constitute a recommendation of the product by the University of Florida's Institute of Food and Agricultural Sciences, nor does it imply its approval to the exclusion of other products.