Maryland’s Lawn Fertilizer Law prohibits residents and lawn care professionals from fertilizing lawns with nitrogen and phosphorus products between November 16th and February 28th. Fertilizer products may not be used to melt ice and snow on paved surfaces as the runoff has a direct and negative impact on water quality. The law also requires lawn care professionals to be licensed and certified by the Maryland Department of Agriculture. For more information, see mda.maryland.gov/fertilizer