Rules on Low-Phosphorous Fertilizer Aimed at Bay Protection

During the 2009 legislative session, the Maryland General Assembly passed the Chesapeake Bay Phosphorus Reduction Act prohibiting the sale of lawn fertilizer that is not low-phosphorous fertilizer. On or after April 1, 2011, lawn fertilizer sold in Maryland must contain not more than 5 percent of available phosphoric acid.

Fertilizers with higher concentrations of phosphorus will be allowed only in special situations and for new lawns and turf. Newly planted areas require more phosphorus to promote root growth, while established plants and turf need very little phosphorus.

The legislation helps protect the Chesapeake Bay from high concentrations of phosphorus that can lead to algae blooms and oxygen depletion. In support of this initiative, the Calvert County Board of County Commissioners passed a resolution in September 2009 to curb the use of high-phosphate fertilizers on county property.

County residents can do their part now by seeking out low phosphorus fertilizers for lawn treatment. It is also a good practice to conduct soil tests before applying fertilizers so that treatments are tailored for local soil conditions.

Learn More
Download a fact sheet on lawns and the Chesapeake Bay from the University of Maryland Extension.