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 space. Use a Dutch bucket or media bed with trellis support (2–3 m of climbing height). EC 1.6-2.4 mS/cm. pH 6.0-7.0. Temperature: 18–30°C (warm-season; frost kills the plant). Moderate to high light (DLI 20-30 mol/m2/day). From seed to first harvest: 60-70 days, roughly a week later than bush beans but with a much longer harvest window (6-8 weeks of continuous production versus 2-3 for bush types). Harvest snap beans daily when the pods are pencil-thick and snap cleanly; regular picking is critical, since leaving overripe pods on the vine signals the plant to stop producing. As a legume the plant fixes nitrogen via Rhizobium in soil, though sterile hydroponic media may need inoculation. Each vine yields 0.5–1 kg of pods over the season, two to three times a bush plant, and the vertical 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. |