Phosphorous is another major element needed for plant growth and is the second number in a fertilizer analysis. It is generally required in smaller amounts than either nitrogen or potassium but plays a critical role in the establishment of turfgrasses. On soils that are low in phosphorous, a light application of this element will increase the growth rate during establishment. High levels of phosphorous can cause problems with turfgrass growth. Centipedegrass is especially sensitive to high phosphorous levels, so it is important to submit soil samples for nutrient analysis on a regular basis.
Potassium is the third major element and the last number on a fertilizer analysis.
This element is almost as important to turfgrass growth as nitrogen. Potassium is critical for plant growth from the establishment phase through complete coverage. Adequate levels of potassium in the soil will allow the plant to withstand environmental as well as mechanical stresses. Most turfgrasses will better tolerate heat, cold and drought situations when potassium levels are sufficient. Diseases may become less of a problem, too.