Silver wattle (mimosa) Acacia dealbata
Silver wattle (mimosa) (Acacia dealbata) is an evergreen perennial tree in the Fabaceae family, native to South-eastern Australia and Tasmania. It grows 6–15 m (20–49 ft) tall and 4–10 m (13–33 ft) wide, wants full sun and low water, and is hardy to about -8 °C (18 °F). Space plants about 6 m (20 ft) apart.
Plan Silver wattle (mimosa) in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Silver wattle (mimosa) at a glance
| Type | Perennial tree, evergreen |
|---|---|
| Family | Fabaceae |
| Mature height | 6–15 m (20–49 ft) |
| Mature spread | 4–10 m (13–33 ft) |
| Spacing | 6 m (20 ft) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance moderate, waterlogging tolerance low |
| Soil pH | 5–7 |
| Cold hardiness | About -8 °C (18 °F) once established (roughly USDA zone 8) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | from about February for 4–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | South-eastern Australia and Tasmania |
| Common in gardens of | 🇦🇺 Australia, 🇫🇷 France, 🇿🇦 South Africa |
| Invasive in | South Africa (NEMBA 1b), Australia (outside its native range), Mediterranean Europe (Portugal, Spain, Italy, France): check local rules before planting |
Is Silver wattle (mimosa) toxic?
- People: not well documented
- Cats: not well documented
- Dogs: not well documented
Not documented as toxic; the pollen is a common hay-fever allergen.
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 Silver wattle (mimosa)
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 Silver wattle (mimosa) in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- The Huntington (1 plants)
- UC Botanical Garden, Berkeley (1 plants)
Questions about Silver wattle (mimosa)
- How far apart should I plant Silver wattle (mimosa)?
- About 6 m (20 ft) apart, centre to centre. A mature plant spreads 4–10 m (13–33 ft).
- Does Silver wattle (mimosa) need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Silver wattle (mimosa) need?
- Low water. Drought tolerance is moderate and waterlogging tolerance low.
- How cold-hardy is Silver wattle (mimosa)?
- It tolerates about -8 °C (18 °F) once established, roughly USDA zone 8.
- When does Silver wattle (mimosa) flower?
- From about February for 4–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Silver wattle (mimosa) poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people not well documented. Not documented as toxic; the pollen is a common hay-fever allergen.
- What grows well with Silver wattle (mimosa)?
- "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).
- Australian native plant profiles, Australian National Botanic Gardens / Australian Plants Society
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- PlantZAfrica, South African National Biodiversity Institute
- CABI Invasive Species Compendium, CABI
Notes and assumptions
- Fast-growing and short-lived (20 to 30 years); suckers freely and spreads by seed after fire. Avoid planting near bushland.
- Flowers in late winter (January to March on the Riviera); needs lime-free soil.
- Typical garden-form values; 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