Phosphorus

Phosphorus is a major component of plant cells; it is important for cell division and growth. Phosphorus promotes strong root growth to keep the grass plants healthy through the stresses of the different seasons. A key function of phosphorus is the storage and transfer of energy throughout the plant. 

Symptoms of phosphorus deficiency include discoloration of leaves, which may become quite dark, susceptibility to damage in colder months, stunted growth and low density of the grass plants. 

Phosphorus is needed in lower quantities than nitrogen, a low-level application twice a year will help keep the grass healthy and resistant.