Broadleaf Banksia (Banksia robur) is a multistemmed coastal shrub from eastern Australia, grown for its large leathery leaves and bold flower spikes. It does best in sandy or peaty soil with a sunny spot and extra water, especially during active growth.
Family
Proteaceae (Protea family)
Grows as
Shrub, Fern
Light
Full sun
Water
Water generously during active growth and dry spells; it tolerates seasonally damp soil.
Soil
Sandy or peaty, free-draining but moisture-retentive mix.
Temperature
Frost-tender; protect below about 0 °C, with a warm to mild tropical to subtropical range suited to its native climate.
How easy
Moderate
Native range
E. Australia
Climate
wet tropical
About
Banksia robur, commonly known as swamp banksia, is a species of flowering plant in the family Proteaceae. It grows in sand or peaty sand in coastal areas from Cooktown in north Queensland to the Illawarra region on the New South Wales south coast. It is often found in areas which are seasonally inundated. It grows as a multistemmed shrub to 3 m (10 ft) tall, with large, leathery tough green leaves with serrated margins up to 30 cm (12 in) long and 10 cm (4 in) wide. The new growth is colourful, in shades of red, maroon or brown with a dense felt-like covering of brown hairs.
Hybrids with its close relative, B. oblongifolia (fern-leaved banksia) can be sometimes found where both species occur (such as near Bulli in the Illawarra), with features intermediate between both species.
How to grow it
As B. robur naturally occurs in wet areas (hence the common name) on sandy soils, these make the best growing conditions. It appreciates a sunny aspect and extra water, especially when actively growing and during dry spells. Propagation from seed is reliable. Hardened pencil-thickness stems have been struck successfully as cuttings.
Where it grows
Banksia robur is native to coastal eastern Australia, where it is found from New South Wales to north Queensland. The Banksia Atlas recorded it as occurring along two stretches of coastline: from Wollongong to South West Rocks in New South Wales, then from Brunswick Heads in northern New South Wales to Shoalwater Bay in Queensland (with a 200 km gap around Rockhampton), and isolated populations near Bowen, Julatten and Cooktown in north Queensland.
Text excerpted from the Wikipedia article Banksia robur by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.