Butterfly pea Clitoria ternatea
Butterfly pea (Clitoria ternatea) is an evergreen perennial flowering plant in the Fabaceae family, native to Tropical Asia. It grows 2–4 m (6.6–13 ft) tall and 1–2 m (3.3–6.6 ft) wide, wants full sun and moderate water, and is hardy to about 5 °C (41 °F). Space plants about 80 cm (31 in) apart.
Plan Butterfly pea in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Butterfly pea at a glance
| Type | Perennial flowering plant, evergreen |
|---|---|
| Family | Fabaceae |
| Mature height | 2–4 m (6.6–13 ft) |
| Mature spread | 1–2 m (3.3–6.6 ft) |
| Spacing | 80 cm (31 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance low |
| Soil pH | 5.5–7.5 |
| Cold hardiness | About 5 °C (41 °F) once established (roughly USDA zone 11) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | about 9–14 weeks after planting, for 17–34 weeks |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Yes: flowers (tea and colouring), young pods |
| Native to | Tropical Asia |
| Common in gardens of | 🇹🇭 Thailand, 🇸🇬 Singapore |
Is Butterfly pea toxic?
- People: mildly toxic
- Cats: not well documented
- Dogs: not well documented
- Parts: seeds, roots
Roots and seeds are purgative or emetic; the blue flowers are used as tea and food colouring.
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 Butterfly pea
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
See Butterfly pea in a botanical garden
It grows in this sample garden, which you can walk through in 3D:
- Gardens by the Bay (4 plants)
Questions about Butterfly pea
- How far apart should I plant Butterfly pea?
- About 80 cm (31 in) apart, centre to centre. A mature plant spreads 1–2 m (3.3–6.6 ft).
- Does Butterfly pea need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Butterfly pea need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance low.
- How cold-hardy is Butterfly pea?
- It tolerates about 5 °C (41 °F) once established, roughly USDA zone 11.
- When does Butterfly pea flower?
- About 9–14 weeks after planting, for 17–34 weeks.
- Is Butterfly pea poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people mildly toxic. Roots and seeds are purgative or emetic; the blue flowers are used as tea and food colouring.
- What grows well with Butterfly pea?
- "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 C (C: plausible, mixed evidence).
- Flora & Fauna Web, National Parks Board, Singapore
- Plants For A Future database, PFAF
- EcoCrop crop environmental requirements, FAO
Notes and assumptions
- Twining legume; short-lived perennial in the tropics, often grown as an annual outside frost-free areas. Frost-tender.
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