What Are Fertilizer Numbers?

Nitrogen

• The first number on an artificial fertilizer denotes nitrogen, N, the most essential plant nutrient. Nitrogen is a critical component of cells and plays an important role in photosynthesis, fostering rapid growth and enhancing the production of fruit and seeds.

Phosphorus

• The second numeral on the fertilizer denotes phosphorus, P. Phosphorus aids with photosynthesis in plants and helps the plant to synthesize sugars, starches and oils. The nutrient promotes growth and leads to healthy root and flower development. Plants adequately fertilized with phosphorus are more tolerant of cultural stresses.

Potassium

• Potassium, or K, is indicated by the third number on the fertilizer bag. The nutrient helps to increase plant resistance to diseases and improves fruit quality. The nutrient builds protein and aids with the process of photosynthesis.