TAMPA — Homeowners who rely on nitrogen-rich fertilizer to keep their lawns green year-round may soon have to find another way to keep their yards lush.
A model ordinance that would ban the use or sale of fertilizers with nitrogen from June 1 through Sept. 30 — the summer rainy season — was approved this month by the Tampa Bay Estuary Program's policy and management board.
The group, which looks out for the health of Tampa Bay, now wants local cities and counties to pass the rule to reduce pollution in the bay.
Supporters of the ordinance say that during the rainy season most of the nitrogen in the fertilizers washes from lawns and landscaping into lakes, streams, rivers and, ultimately, Tampa Bay. That promotes algae blooms, which suck oxygen from the water, making it unhealthy for fish, birds, sea grass and other wildlife.
The model ordinance also prohibits putting down fertilizers within 10 feet of ponds, lakes, rivers, streams, ditches or any other waterway. The rule would allow code enforcement officers to cite residents and issue fines of up to $500 for violations. But proponents acknowledge enforcement would be difficult.
"I don't think anybody is thinking you're going to have fertilizer police," said Rick Garrity, an estuary board member and director of the Hillsborough County Environmental Protection Commission. "What everybody is going to do is emphasize education."
Local governments may choose to enact all, parts or none of the suggested ordinance.
St. Petersburg City Council member James Bennett said he hopes to get support for all its provisions from his board, including the ban on sales.
"I will argue for that. But if we have to take it in steps and add that later, that's fine," he said. "As a society, we overfertilize. We don't quite need to put down as much as we do."
Bennett, who has been in the landscape business for more than 25 years, said lawns don't need nitrogen during the summer months if it is used the rest of the year and if grass clippings, which decay and provide nitrogen, remain on the lawn after mowing.
"If you really have to have nitrogen, you can do slow release in the springtime, and it will get you through the summer," he said.
Backers of the ordinance also say it will help the region meet U.S. Environmental Protection Agency guidelines for limiting nitrogen in surface water. The EPA is now setting those limits. Once they are in place, cities and counties may have to invest in such things as treatment plants and stormwater ponds to adhere to the guidelines, or pay fines for exceeding them.
Tampa City Council member Linda Saul-Sena, also a member of the estuary program's policy board, said the ordinance addresses that problem with a "really simple, low-tech approach, which is just don't fertilize during the rainy season."
"This is an inexpensive way to protect the water and save our community money," she said.
Officials at the Tampa Bay Estuary Program estimate the ban will take 84 tons of nitrogen out of the bay.
But Erica Santella, technical manager with lawn care giant TruGreen, calls the ban on sales and use of fertilizer the winner of "a popularity contest."
"The blackout period really doesn't have scientific support. It's feel good. It's the less fertilizer you use, it should be better for the water." Some research shows heavy rains don't actually contribute to fertilizer runoff, she said.
Florida lawns need nitrogen year-round not just to stay green, but to promote overall health, she said. Typically, TruGreen recommends fertilizing two to three times from June 1 through Sept. 30.
"It's not so much how often you fertilize, but how much you use altogether. By having this blackout period, people tend to fertilize more than they need to before and more afterward to make up for it," she said.
She said the company backs the idea of fertilizer-free zones and tight regulation of spills. "We understand the problem," she said. "No one's arguing there's not an issue. All we're trying to figure out is how to get to the solution."
But Nanette O'Hara, a spokeswoman for the Tampa Bay Estuary Program, said the ordinance as it is written is "a big move for this region."
"Nitrogen is the biggest polluter of the bay," she said. "As we try to deal with more and more growth in the future, we're going to have to continually offset nitrogen going into the bay. This is one part of the strategy."
Janet Zink can be reached at email@example.com or (813) 226-3401.