Rain tree Samanea saman
Rain tree (Samanea saman) is an evergreen perennial tree in the Fabaceae family, native to Central America and northern South America (seasonal dry forest and savanna). It grows 15–25 m (49–82 ft) tall and 25–40 m (82–131 ft) wide, wants full sun and moderate water, and is hardy to about 5 °C (41 °F). Space plants about 25 m (82 ft) apart.
Plan Rain tree in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Rain tree at a glance
| Type | Perennial tree, evergreen |
|---|---|
| Family | Fabaceae |
| Mature height | 15–25 m (49–82 ft) |
| Mature spread | 25–40 m (82–131 ft) |
| Spacing | 25 m (82 ft) 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 | 5–8.5 |
| Cold hardiness | About 5 °C (41 °F) once established (roughly USDA zone 11) |
| Heat stress | Likely above about 42 °C (108 °F) |
| Flowering | from about March for 6–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Central America and northern South America (seasonal dry forest and savanna) |
| Common in gardens of | 🇲🇽 Mexico, 🇧🇷 Brazil, 🇸🇬 Singapore, 🇹🇭 Thailand |
| Invasive in | Vanuatu, Hawaii (naturalised): check local rules before planting |
Is Rain tree toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
No toxicity reported; the sweet pod pulp is fed to cattle.
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 Rain tree
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
See Rain tree in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Singapore Botanic Gardens (8 plants)
- Gardens by the Bay (3 plants)
- Jardim Botânico do Rio de Janeiro (1 plants)
- Na ʻĀina Kai Botanical Gardens (3 plants)
Questions about Rain tree
- How far apart should I plant Rain tree?
- About 25 m (82 ft) apart, centre to centre. A mature plant spreads 25–40 m (82–131 ft).
- Does Rain tree need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Rain tree need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance low.
- How cold-hardy is Rain tree?
- It tolerates about 5 °C (41 °F) once established, roughly USDA zone 11.
- When does Rain tree flower?
- From about March for 6–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Rain tree poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. No toxicity reported; the sweet pod pulp is fed to cattle.
- What grows well with Rain tree?
- "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).
- Flora & Fauna Web, National Parks Board, Singapore
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- CABI Invasive Species Compendium, CABI
- UF/IFAS Extension tropical and subtropical fruit and landscape publications, University of Florida
Notes and assumptions
- Tropical lowland plant: outdoors only where it never frosts (as in Singapore); elsewhere it needs a heated glasshouse.
- A huge umbrella crown, much wider than tall, laden with ferns and orchids in Singapore; leaflets fold up at dusk and before rain.
- Typical garden-form values; cultivars and local conditions differ.
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