Phosphorus (P) is an essential plant nutrient and a common component of many turfgrass nutrition programs. Although P application can improve turfgrass quality in some soils, most soils of Kentucky already have adequate plant-available P to support healthy turfgrass growth. What is the function of P within the plant, and how much P is required to sustain acceptable turfgrass in Kentucky? Also, if P applications are necessary, when and how should P be applied?