Fertilizer for Beans (Green): NPK Guide and Application Rates
Green beans are nitrogen-fixing legumes that form a symbiotic relationship with Rhizobium bacteria in the soil. These bacteria colonize root nodules and convert atmospheric nitrogen into a plant-usable form, meaning beans need little to no supplemental nitrogen fertilizer.
Quick Reference
What NPK Ratio is Best for Beans (Green)?
The recommended NPK ratio for beans (green) is 5-10-10. The phosphorus-heavy 5-10-10 ratio supports strong root systems and flower/fruit production in beans (green).
Beans (Green) NPK needs shift at each growth stage. Low nitrogen at planting since beans fix their own during the Seedling phase, then phosphorus and potassium only for bloom support once flowering begins.
NPK by Growth Stage for Beans (Green)
| Growth Stage | NPK Ratio | Notes |
|---|---|---|
| Seedling | 5N 10P 10K N 5% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Low nitrogen at planting since beans fix their own |
| Vegetative | 5N 10P 10K N 5% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Beans provide their own nitrogen through root nodules |
| Flowering | 0N 10P 10K N 0% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Phosphorus and potassium only for bloom support |
| Fruiting | 0N 10P 10K N 0% Nitrogen: leaf and stem growth P 10% Phosphorus: roots and flowers K 10% Potassium: health and disease resistance Learn more about NPK | Avoid nitrogen during pod production |
When Should You Fertilize Beans (Green)?
In zone 3, start fertilizing beans (green) in June. In zone 10, begin as early as February. Apply every 6 weeks through the growing season.
Which Zones Can Grow Beans (Green)?
Beans (Green) grows in USDA zones 3 through 10, spanning a 8-zone range.
Fertilization Start by Zone
| Zone | Start Month |
|---|---|
| Zone 3 | June |
| Zone 4 | May |
| Zone 5 | May |
| Zone 6 | April |
| Zone 7 | April |
| Zone 8 | March |
| Zone 9 | March |
| Zone 10 | February |
What Are the Best Fertilizer Products for Beans (Green)?
Look for products with an NPK close to 5-10-10. Espoma Garden-tone is the most popular choice among home gardeners for beans (green).
- Espoma Garden-tone
- Dr. Earth Vegetable Garden Fertilizer
- Down to Earth Bio-Fish
Prices vary by retailer and region. Check current pricing before purchasing.
Container and Raised Bed Adjustments for Beans (Green)
Container beans may need a single light feeding of phosphorus-potassium fertilizer at flowering; avoid nitrogen
Common Fertilizing Mistakes with Beans (Green)
- Adding nitrogen fertilizer causes excessive leaf growth and poor pod production
- Over-fertilizing burns bean roots, which are shallow and sensitive
- Failing to inoculate seeds in soil where beans have never grown
Tips for Fertilizing Beans (Green)
- Inoculate seeds with Rhizobium bacteria if planting beans in a new bed for the first time
- Apply only phosphorus and potassium; beans make their own nitrogen
- A light side-dressing of compost at flowering is usually sufficient
Organic Fertilizer Alternatives for Beans (Green)
Sources
Source:Clemson University ExtensionLast updated: