🌿 Nutrition & Feeding
Enter your garden area, the fertilizer's NPK numbers, and your target nitrogen rate. Get the exact amount of fertilizer to apply.
Related Calculators
The three numbers on a fertilizer bag (e.g., 10-10-10) represent the percentage by weight of Nitrogen (N), Phosphorus (P₂O₅), and Potassium (K₂O).
Nitrogen (N) – Drives leafy, green growth. Most important for vegetables, especially leafy greens, corn, and grass.
Phosphorus (P) – Promotes root development, flowering, and fruiting. Important for tomatoes, peppers, and root vegetables.
Potassium (K) – Strengthens cell walls, improves disease resistance and drought tolerance.
| Crop Type | N lbs / 1,000 sq ft |
|---|---|
| Leafy greens, lettuce | 1.5 – 2 |
| Tomatoes, peppers | 1 – 1.5 |
| Root vegetables | 0.5 – 1 |
| Beans, peas (fix N) | 0 – 0.5 |
| Corn, squash | 1.5 – 2 |
| Herbs | 0.5 – 1 |
Fertilizer amount = (Target N rate × Area) ÷ (N% ÷ 100)
For example: to apply 1 lb N per 1,000 sq ft using a 10-10-10 fertilizer: 1 ÷ 0.10 = 10 lbs of fertilizer per 1,000 sq ft.