Garden chart
Fertilizer N-P-K Ratio Guide by Plant Type
The three numbers on a fertilizer bag (like 10-10-10) always appear in the same order: nitrogen (N), phosphorus (P), potassium (K), each as a percentage by weight. Nitrogen drives leafy green growth, phosphorus supports root and flower development, and potassium supports overall plant health and stress tolerance. Match the ratio to what the plant needs most right now, not just its category.
| Plant type / goal | Typical N-P-K ratio | Why |
|---|---|---|
| Lawn (spring green-up) | 20-5-10 or similar high-N | Leafy growth is the goal; roots are already established |
| Lawn (fall feeding) | 10-10-20 or higher-K | Potassium builds winter hardiness and root reserves |
| Leafy vegetables (lettuce, spinach) | 10-5-5 or balanced high-N | Reward leaf mass over flowering or fruiting |
| Fruiting vegetables (tomato, pepper) | 5-10-10 or 3-4-6 | Lower N avoids excess foliage at the expense of fruit |
| Root vegetables (carrot, beet) | 5-10-10 | Phosphorus and potassium support root development |
| Flowering annuals/perennials | 5-10-5 or 'bloom booster' | Phosphorus supports bud and flower formation |
| Houseplants (general foliage) | 20-20-20 balanced, diluted | Balanced growth without pushing rapid leggy growth |
| Trees and shrubs (establishment) | close to balanced, e.g. 10-10-10 | Supports both root and top growth while settling in |
Notes
- Too much nitrogen on fruiting vegetables is the classic cause of a huge, healthy-looking plant that produces little fruit.
- A soil test is the only reliable way to know if phosphorus or potassium are actually deficient — many garden soils already have adequate levels and don't need more.
- Organic fertilizers (fish emulsion, bone meal, compost) release nutrients more slowly than synthetic ones, so their N-P-K numbers are lower but longer-lasting.
Put this into practice
- Lawn Fertilizer CalculatorHow much fertilizer does my lawn need?
- What to Plant This MonthWhat can I plant right now where I live?
More charts like this
- Vegetable Spacing Chart: In-Row and Between-Row DistancesRecommended in-row and between-row spacing for the most commonly grown vegetables, in a raised bed or a traditional row garden.
- Seed Sowing Depth Chart by Vegetable and FlowerHow deep to sow common vegetable and flower seeds directly in the garden, plus days to germination as a rule of thumb.
- Mulch Coverage Chart: Square Feet per Cubic Yard by DepthHow much area one cubic yard of mulch covers at common application depths, plus recommended depth by mulch type.