The largest study to date for Florida on turfgrass and fertilizer use was conducted by the University of Florida’s Institute of Food and Agricultural Sciences. It took eight years and $4.2 million dollars to determine the effectiveness of current state fertilizer recommendations. The study revealed that abstaining from fertilizing during summer months may harm your grass.
The findings dispute the logic behind local ordinances enacted statewide to ban rainy season fertilizer use. For example, officials in Brevard County, Florida, while stopping short of a ban, approved a recommendation that homeowners not use fertilizer between June 1st and September 30th. The ordinances are an attempt to reduce nitrogen and phosphorus runoff, which is the prime suspect in triggering massive fish-killing algae blooms.
“Many of the ordinances that have been put out there, on the surface, appear to be doing good things, but the science is suggesting it likely is not,” said Bryan Unruh, an associate professor of environmental horticulture at the University of Florida. “The ban encourages excess fertilization prior to the rainy season, when the plants’ ability to use that fertilizer is considerably less.”
These findings may result in changes to the statewide ordinances. Florida has more than five million acres of residential and commercial turfgrass.