Fertilizer N-P-K
Lawn & Garden · 8 specs
Direct Answer
Fertilizer labels display three numbers representing percentage by weight of Nitrogen (N) for foliage growth, available Phosphate (P2O5) for root development, and soluble Potash (K2O) for drought and cold hardiness.
Source: Association of American Plant Food Control Officials (AAPFCO) / USDA · Last reviewed Aug 28, 2026
Specs
| Governing Standards | AAPFCO Guaranteed Analysis / USDA Fertilizer Sizing Guidelines |
| First Number (N) | Nitrogen % | Promotes rapid leaf blade growth and green chlorophyll synthesis |
| Second Number (P) | Phosphate (P2O5) % | Stimulates root establishment and blossom/fruit set |
| Third Number (K) | Potash (K2O) % | Strengthens cell walls for drought, heat, and disease resistance |
| Balanced All-Purpose (10-10-10) | 10% N, 10% P2O5, 10% K2O (General vegetable garden & flower bed standard) |
| Lawn Maintenance (24-0-11) | High nitrogen turf blend for established lawns without phosphorus runoff |
| Starter Fertilizer (18-24-12) | High phosphorus blend for new sod establishment and seed germination |
| 1.0 lb Nitrogen per 1k sq ft Rule | Lbs of product = 100 ÷ Nitrogen % (e.g. 20-5-10 requires 5.0 lbs/1,000 sq ft) |
Standard N-P-K Formulations & Target Applications
| Grade (N-P-K) | Ratio | Primary Target Application | Product Rate for 1.0 lb N / 1k sq ft |
|---|---|---|---|
| 10-10-10 | 1:1:1 | Vegetable gardens, annual flowerbeds, general shrubs | 10.0 lbs per 1,000 sq ft |
| 20-20-20 | 1:1:1 | Water-soluble houseplant and greenhouse feeding | 5.0 lbs per 1,000 sq ft |
| 24-0-11 | 2:0:1 | Established turfgrass maintenance (Zero-phosphorus lawn) | 4.17 lbs per 1,000 sq ft |
| 32-0-4 | 8:0:1 | Early spring high-growth residential turfgrass | 3.12 lbs per 1,000 sq ft |
| 18-24-12 | 3:4:2 | New lawn seeding, overseeding, and sod establishment | 5.55 lbs per 1,000 sq ft |
| 5-10-5 | 1:2:1 | Tomato, root vegetable, and flowering bulb beds | 20.0 lbs per 1,000 sq ft |