Bush beans

Quick facts

Category

fruiting

Difficulty

beginner

Days to harvest

50 to 65 days

Harvest type

continuous production over weeks or months

Spacing

15 cm between plants

Environment

Temperature

18–30°C

pH

6 to 7

EC (hydroponic)

1.5 to 2.2 mS/cm

Daily light

18 to 25 mol/m²/day (strict, will fail outside this range)

Climate and zones

USDA zones

10 to 13 (winter low around -1°C or warmer)

Frost tolerance

frost sensitive (dies at first frost)

Season

warm (summer crops, frost-sensitive)

Viable growing environments:

• outdoor year-round (in zone)
• outdoor in growing season (annual)
• unheated greenhouse / hoop house
• heated greenhouse
• indoor (heated home)
• indoor hydroponics under grow lights

USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.

Growing systems

Bush beans works in:

• media bed (ebb and flow)
• wicking bed
• soil bed
• drip / Dutch buckets

Growing media

The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (bush beans works in the media listed below).

Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.

Nutrient demand by stage

NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.

Companion-growing notes

• Heavy uptake of potassium. Co-grown crops with the same demand will end up deficient even at "correct" EC. Plan around this in shared reservoirs.
• High transpiration. Reservoir level will need regular top-ups during fruiting or flowering.

Aquaponics suitability

Compatible with typical aquaponics nutrient profiles. 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 moderately successful hydroponic crop. The bush habit means no trellis is needed, keeping the system simple. EC 2.0-3.0 mS/cm. pH 5.8-6.5. Temperature: 18–28°C (warm-season crop; growth stops below 15°C). Moderate to high light (DLI 16-22 mol/m2/day). DWC, media beds, or Dutch bucket systems all work. Beans are legumes that fix nitrogen through root nodule bacteria (Rhizobium); in hydroponic systems without soil, these bacteria may be absent, so the plants rely entirely on the nutrient solution for nitrogen. From seed to first harvest: 50-65 days. Harvest snap beans when pods are pencil-thick and snap cleanly; delay causes tough, stringy pods. Bush beans set most of their pods within a 2-3 week window, then production declines. Succession plant every 3-4 weeks for continuous harvest. Each plant produces roughly 200–400 g of pods. Common issues: bean beetles (in open greenhouses), powdery mildew (improve airflow), and blossom drop (caused by heat stress above 32°C). For aquaponics, bush beans grow well in media beds and add visual variety alongside leafy greens.

Further reading

• What to grow in an aquaponics system (and what won't work)