Sturt’s desert pea Swainsona formosa
Sturt’s desert pea (Swainsona formosa) is an annual flowering plant in the Fabaceae family, native to Arid inland Australia. It grows 10–30 cm (4–12 in) tall and 60 cm–1.5 m (24 in–4.9 ft) wide, wants full sun and low water, and is hardy to about 2 °C (36 °F). Space plants about 80 cm (31 in) apart.
Plan Sturt’s desert pea in your garden →
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Sturt’s desert pea at a glance
| Type | Annual flowering plant |
|---|---|
| Family | Fabaceae |
| Mature height | 10–30 cm (4–12 in) |
| Mature spread | 60 cm–1.5 m (24 in–4.9 ft) |
| Spacing | 80 cm (31 in) centre to centre |
| Sun | Full sun, at least 8 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 6–8.5 |
| Cold hardiness | About 2 °C (36 °F) once established (roughly USDA zone 10) |
| Heat stress | Likely above about 45 °C (113 °F) |
| Flowering | about 13–17 weeks after planting, for 6–10 weeks |
| Days to maturity | About 150 days from planting |
| Wind tolerance | Moderate |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Arid inland Australia |
| Common in gardens of | 🇦🇺 Australia |
Is Sturt’s desert pea toxic?
- People: not well documented
- Cats: not well documented
- Dogs: mildly toxic
Some Swainsona species poison livestock (swainsonine); treat as unsafe.
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 Sturt’s desert 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
Questions about Sturt’s desert pea
- How far apart should I plant Sturt’s desert pea?
- About 80 cm (31 in) apart, centre to centre. A mature plant spreads 60 cm–1.5 m (24 in–4.9 ft).
- Does Sturt’s desert pea need full sun?
- Full sun: at least 8 hours of direct sun a day.
- How much water does Sturt’s desert pea need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Sturt’s desert pea?
- 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 Sturt’s desert pea flower?
- About 13–17 weeks after planting, for 6–10 weeks.
- Is Sturt’s desert pea poisonous to cats and dogs?
- For cats it is not well documented; for dogs mildly toxic; for people not well documented. Some Swainsona species poison livestock (swainsonine); treat as unsafe.
- What grows well with Sturt’s desert 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 B (B: extension service or peer-reviewed).
- Australian native plant profiles, Australian National Botanic Gardens / Australian Plants Society
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
Notes and assumptions
- Floral emblem of South Australia: blood-red claw flowers with a glossy black “eye” on sprawling grey stems. Hates root disturbance and wet; often grown as an annual or grafted.
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