Pole beans
Phaseolus vulgaris
Also known asClimbing beans · Runner beans (UK, but technically different species) · Rampicante · Kletterbohnen
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 3–12 (winter low around -40°C)
- Frost
- frost sensitive (dies at first frost)
- Season
- warm (summer, frost-sensitive)
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Perlite (Expanded volcanic glass) | neutral / inert | very low | low |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 1 |
| vegetative | 1 | 2 | 2 | 1.6 |
| flowering | 1 | 2 | 3 | 2 |
| fruiting | 1 | 2 | 3 | 2.2 |
Companion-growing notes
- High transpiration. Regular reservoir top-ups needed during fruiting.
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
A productive vine crop for hydroponic systems with vertical growing space. Dutch bucket or media bed with trellis support (2–3 m of climbing height). EC 2.0-3.0 mS/cm. pH 5.8-6.5. Temperature: 18–28°C (warm-season; frost kills the plant). Moderate to high light (DLI 16-22 mol/m2/day). From seed to first harvest: 60-70 days, about a week later than bush beans but the harvest period is much longer (6-8 weeks of continuous production vs. 2-3 weeks for bush types). Harvest snap beans daily when pods are pencil-thick and snap cleanly. Regular picking is critical: leaving overripe pods on the vine signals the plant to stop producing. As a legume, nitrogen fixation via Rhizobium occurs naturally in soil but may require inoculation in sterile hydroponic media. Each vine produces 0.5–1 kg of pods over the season (2-3x the yield of a bush bean plant). The vertical growth habit makes efficient use of floor space.
Notable varieties
| Cultivar | Type | Origin | Days | Notes |
|---|---|---|---|---|
| Kentucky Wonder | heirloom | 70 | 1864 heirloom, the most common pole bean variety in the US. Stringless when picked young, productive, vigorous. The default home-garden pole bean for a reason. | |
| Blue Lake Pole | open pollinated | 65 | Round, smooth, deep green pods. The standard commercial pole bean; what most canned and frozen green beans are. More uniform than Kentucky Wonder but slightly less productive. | |
| Rattlesnake | heirloom | 75 | Striped purple-green pods (pretty), drought-tolerant, heat-tolerant. Better than Kentucky Wonder in hot dry summers. | |
| Fortex | open pollinated | Vilmorin, late 1990s | 70 | Very long thin pods (20-25 cm) that stay tender even at full size. The 'fancy market' pole bean; what fancy CSAs grow. |