Lima beans
Phaseolus lunatus
Also known as: Butter beans, Madagascar beans, Sieva beans, Pallar
Quick facts
- Category
- fruiting
- Difficulty
- intermediate
- Days to harvest
- 75 to 100 days
- Harvest type
- continuous production over weeks or months
- Spacing
- 15 cm between plants
Environment
- Temperature
- 21–30°C
- pH
- 6 to 7
- EC (hydroponic)
- 1.6 to 2.4 mS/cm
- Daily light
- 22 to 30 mol/m²/day
Climate and zones
- USDA zones
- 4 to 12 (winter low around -34°C or warmer)
- Frost tolerance
- frost sensitive (dies at first frost)
- Season
- warm (summer crops, frost-sensitive)
Viable growing environments:
- outdoor in growing season (annual)
- unheated greenhouse / hoop house
- heated greenhouse
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
Lima beans works in:
- drip / Dutch buckets
- media bed (ebb and flow)
- soil bed
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 (lima beans works in the media listed below).
| Medium | pH effect | Water retention | Bacterial surface |
|---|---|---|---|
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Perlite (Expanded volcanic glass) | neutral / inert | very low | low |
| Soil-based mix (Potting soil) | varies by source | high | high |
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.
| Stage | N | P | K | EC target (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. 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 warm-season legume for media bed or container hydroponic systems. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 20–30°C (more heat-demanding than common beans; doesn't germinate below 18°C). High light (DLI 16-22 mol/m2/day). Bush types are more practical for contained growing spaces. From seed to fresh lima harvest: 65-80 days (bush types). Harvest for fresh eating when pods are plump and bright green but seeds haven't yet hardened. For dried limas: leave pods on the plant until fully brown and dry (100-120 days). Each plant produces moderate yields (150–300 g fresh pods). As a legume, nitrogen fixation may be limited in sterile hydroponic media without Rhizobium inoculant. Lima beans drop their blossoms in temperatures above 32°C or during drought stress, which is the most common production issue. Consistent moisture and moderate temperatures during flowering are critical for pod set.
Verified against: u-florida-ifas, rhs-uk, cornell-cea. Last reviewed 2026-05-15.