Soybean (edamame) Glycine max
Soybean (edamame) (Glycine max) is an annual vegetable in the Fabaceae family, native to East Asia (China). It grows 50 cm–1.2 m (20 in–3.9 ft) tall and 30–50 cm (12–20 in) wide, wants full sun and moderate water, and is hardy to about 2 °C (36 °F). Space plants about 10 cm (4 in) apart.
Plan Soybean (edamame) in your garden →
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Soybean (edamame) at a glance
| Type | Annual vegetable |
|---|---|
| Family | Fabaceae |
| Mature height | 50 cm–1.2 m (20 in–3.9 ft) |
| Mature spread | 30–50 cm (12–20 in) |
| Spacing | 10 cm (4 in) centre to centre |
| Sun | Full sun, at least 7 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance low |
| Soil pH | 6–7 |
| Cold hardiness | About 2 °C (36 °F) once established (roughly USDA zone 10) |
| Heat stress | Likely above about 35 °C (95 °F) |
| Flowering | about 6–8 weeks after planting, for 3–5 weeks |
| Days to maturity | About 90 days from planting |
| Wind tolerance | Low |
| Pollinator value | Low |
| Edible | Yes: immature seeds (edamame, cooked), mature seeds (cooked or processed), sprouts |
| Native to | East Asia (China) |
| Common in gardens of | 🇯🇵 Japan, 🇨🇳 China, 🇺🇸 United States, 🇧🇷 Brazil, 🇰🇷 South Korea |
Is Soybean (edamame) toxic?
- People: mildly toxic
- Cats: not well documented
- Dogs: not well documented
- Parts: raw seeds
Raw soybeans contain trypsin inhibitors and lectins that cause stomach upset; cook thoroughly.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Soybean (edamame)
Good neighbours
- good With Sweet corn: "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils. Evidence C
Keep apart or take care
- caution With Alliums (onion family): Onions, garlic and leeks are said to stunt beans and peas (allium root exudates may reduce nodulation). Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Alliums (onion family): Beans and peas are traditionally kept away from onions, garlic and leeks. Traditional companion-planting advice; controlled trials are few, so treat it as a soft preference. Evidence D
- caution With Fennel: Fennel is reported to suppress beans and peas growing next to it. Evidence C
Shared pests and diseases
- Root rots: Fusarium and Aphanomyces root rots build up where legumes repeat. Evidence C
Questions about Soybean (edamame)
- How far apart should I plant Soybean (edamame)?
- About 10 cm (4 in) apart, centre to centre. A mature plant spreads 30–50 cm (12–20 in).
- Does Soybean (edamame) need full sun?
- Full sun: at least 7 hours of direct sun a day.
- How much water does Soybean (edamame) need?
- Moderate water. Drought tolerance is low and waterlogging tolerance low.
- How cold-hardy is Soybean (edamame)?
- It tolerates about 2 °C (36 °F) once established, roughly USDA zone 10. As an annual it is usually planted out after the last frost.
- When does Soybean (edamame) flower?
- About 6–8 weeks after planting, for 3–5 weeks.
- Is Soybean (edamame) poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people mildly toxic. Raw soybeans contain trypsin inhibitors and lectins that cause stomach upset; cook thoroughly.
- What grows well with Soybean (edamame)?
- "Three sisters": climbing beans use corn as a support and fix nitrogen; the benefit to the corn is modest but real in low-input soils.
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- FAO Irrigation and Drainage Paper 56 — Crop Evapotranspiration, FAO
- University extension gardening guides (general), Various land-grant university extensions
- EcoCrop crop environmental requirements, FAO
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Edamame (picked green) assumed; flowering is controlled by daylength, so sowing date and cultivar maturity group matter.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Bush bean Phaseolus vulgaris
- Garden pea Pisum sativum
- Sweet pea Lathyrus odoratus
- Runner bean Phaseolus coccineus
- Broad bean (fava) Vicia faba
- Lima bean Phaseolus lunatus
- Cowpea (black-eyed pea) Vigna unguiculata
- Yardlong bean Vigna unguiculata subsp. sesquipedalis