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.
More on Fertilizer
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