What do the three numbers found on a fertilizer label represent?

The three numbers on a fertilizer label represent the levels of essential nutrients required for plant growth, specifically Nitrogen, Phosphorus, and Potassium. These three nutrients are commonly referred to as N-P-K.

Nitrogen is crucial for the development of green foliage and overall plant growth, as it is a vital component of chlorophyll, the molecule that plants use in photosynthesis. Phosphorus is essential for the formation of roots, flowers, and fruits, often influencing the quality and yield of crops. Potassium plays a key role in regulating various plant processes, including water uptake, enzyme activation, and disease resistance.

The numbers indicate the percentage by weight of each nutrient in the fertilizer. For example, a fertilizer labeled 10-20-10 would contain 10% nitrogen, 20% phosphorus, and 10% potassium. This standardized format helps gardeners and farmers select the appropriate fertilizer based on the specific nutrient needs of their plants or soil conditions.