What do the three numbers on a fertilizer label indicate?

The three numbers on a fertilizer label represent the relative percentages of three essential nutrients: nitrogen, phosphorus, and potassium. This format is often referred to as the N-P-K ratio.

Nitrogen is critical for promoting leafy, vegetative growth, phosphorus is important for root development, flower and fruit production, and potassium helps in overall plant health and disease resistance. Each of these nutrients plays a distinct and vital role in plant growth and development, making their balance important for optimal plant health.

Understanding this labeling system is crucial for farmers and gardeners as it helps them select the right fertilizer based on the specific nutritional needs of their plants during different growth stages. The other options provided represent micronutrients or elements that, while important for plant health, do not relate to the primary nutrient designation reflected on a fertilizer label.