What is the earliest date of the year on which nitrogen or phosphorus may be applied to turf?

The earliest date for the application of nitrogen or phosphorus to turf is March 1. This date is significant because it marks the onset of the growing season for many turfgrass species in Maryland, allowing for effective nutrient uptake as temperatures start to rise. Fertilizing too early in the year can lead to runoff during winter rains or early spring thaws, as the ground may still be frozen or saturated, resulting in potential environmental harm and inefficiencies in nutrient absorption by the grass. By March 1, the soil temperatures generally rise enough for grass to start actively growing, thus maximizing the benefits of fertilizer applications. This guideline helps to promote responsible fertilizer use in light of environmental regulations and best management practices.