Ordinances passed by Pinellas in 2010 and by Tampa in 2011 prohibit the sale or application of nitrogen-containing fertilizer from June 1 through Sept. 30 in those jurisdictions. Hillsborough County communities outside the Tampa city limits are not subject to the ban.
The restrictions were enacted in an effort to reduce the amount of nitrogen washed into streams, rivers and bays during the rainy summer months. Nitrogen overload is the main cause of algae growth, oxygen depletion and fish kills in state waterways, scientists say.
“Storm-water runoff in general is a major source of nitrogen to the bay,” said Nanette Holland O’Hara, public outreach coordinator for the Tampa Bay Estuary Program. “About 20 percent of the storm-water runoff is coming from residential runoff which includes fertilizer.”
The 40 or so local governments around Florida that have passed some type of summertime restriction on nitrogen-based fertilizer did so despite intense opposition from fertilizer and yard maintenance companies.
Industry lobbyists also tried this spring, as they have in years past, to get the Florida Legislature to prevent local governments from passing rainy season fertilizer bans. Their efforts failed.
Opponents of the fertilizer bans say lawns need nitrogen during the summer months when most growth occurs. During that period, they say, the plant’s roots suck up nitrogen quickly, leaving little residue to wash into storm drains.
Instead of a ban, industry lobbyists argued for educating homeowners on proper application techniques.
Brad Morgan, of Morgan Horticultural Services, said the bans could actually be counterproductive to what environmentalists hope to achieve. Many residents and commercial applicators will put twice as much fertilizer out in May and October to compensate for the summer ban, he said.
“You’re going to get a lot of runoff because the plant is not going to be able to take it up as fast,” Morgan said.
Plus, the ban is uneven. The Hillsborough County Commission declined to enact a total-summertime prohibition, despite recommendations from their own county Environmental Protection Commission and from scientists with the Tampa Bay Estuary Program.
Instead, the commission passed a weaker rule that prohibits nitrogen fertilizer use while it is raining, during a flood watch or 36 hours before a storm expected to dump 2 inches or more of rain in 24 hours.
That means residents in unincorporated Hillsborough County, where two-thirds of the county’s population lives, can buy nitrogen-containing fertilizer at their local stores. Tampa residents can easily drive outside the city limits to get theirs.
“No matter what ban is in effect, there are always going to be companies that put out fertilizer too heavy,” Morgan said. “You’re still going have pollution based on people using improper practices.”
Environmentalists disagree, saying the bans are an important step in cleaning up algae-choked waterways.
O’Hara, the estuary program spokeswoman, said federal and state laws have been effective in reducing — even eliminating — nutrient pollution from sewage plants and manufacturing discharges.
“We’re now trying to reduce sources of nitrogen that are more complex and more difficult to control and this is one of them,” she said.
Environmentalists say there are good “summer safe” products on the shelves that use iron to green up lawns.
“Stores are being great about compliance,” O’Hara said. “It makes it very easy for consumers because, if they’re going out Saturday morning, everything on the shelf should be a compliant product.”