NPK Ratio
The three numbers on every bag of fertilizer, for example, 28-0-6. They represent the percentage by weight of Nitrogen (N), Phosphorus (P), and Potassium (K). A 28-0-6 bag is 28% nitrogen, 0% phosphorus, and 6% potassium.
NPK stands for Nitrogen (N), Phosphorus (P), and Potassium (K), the three primary macronutrients that lawns need to thrive. Every fertilizer bag is required by law to display these three numbers.
Nitrogen (N), the first number. Drives blade growth and green color. Most lawns need regular nitrogen applications.
Phosphorus (P), the middle number. Supports root development and seed germination. Established lawns usually need very little. Many fertilizers show 0 for phosphorus.
Potassium (K), the last number. Strengthens cells, improves drought and cold tolerance, and supports disease resistance. Important in fall fertilizers.
Example: A bag labeled 28-0-6 is 28% nitrogen, 0% phosphorus, and 6% potassium. In a 50 lb bag, that's 14 lbs of nitrogen and 3 lbs of potassium.
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