What do the Numbers Mean?

All fertilizers have a label which list the percentages of the three major nutrients that they contain in the following order N-P-K. Which means that a fertilizer listing of 28-7-14, for example, is 28% N (Nitrogen), 7% P (Phosphorous), and 14% K (Potassium). Some fertilizers contain additional trace elements, slow release sources of nitrogen and/or organic sources of nutrients.

N = Nitrogen (N).
Nitrogen is the first number in the analysis of the bag. Nitrogen is a component of chlorophyll (responsible for green color of plants). Nitrogen is required for nearly all growth processes in turf. Nitrogen is important for new and established lawns. Top growth occurs at the expense of root growth, so excessive amounts of Nitrogen can restrict root growth.

P = Phosphorous (P2O5).
Phosphorous is the second number in the analysis. This nutrient is for root development and is especially important for young turf. The rapid growth associated with germination requires phosphorous, therefore is essential in starter fertilizers. Less is required in established turf.

K = Potassium (K2O).
Potassium, also know as Potash, is associated with the plant's ability to withstand stress. When supplied to the plant along with adequate amounts of Nitrogen, potassium thickens the cell wall. This makes the plant better able to withstand drought, insects, disease and temperature extremes.