Brachychiton acerifolius Seeds | Illawarra Flame Tree
LATIN NAME: Brachychiton acerifolius
COMMON NAME: Illawarra Flame Tree
Plant Profile
Illawarra Flame Tree is a large deciduous tree of the rainforests and wet sclerophyll forests of eastern Australia, eventually reaching twenty to thirty metres, though much smaller in cooler gardens. For most of the year it is a plain green umbrella of maple-like leaves, but in early summer, after a dry spring, the whole canopy can drop its leaves and cover the bare branches in drooping sprays of scarlet, bell-shaped flowers.
The flowering is spectacular but irregular; a tree may blaze one year and bloom thinly the next, and young trees may take a decade or more to make their first real display. The smooth green trunk and the boat-shaped woody follicles, packed with bristly yellow seeds, carry their own garden interest.
Science & Biotechnology
The tree sits in the brachychiton group of the mallow family, where it has featured in work on seed biology and propagation, including the treatment of its hard coat and the germination behaviour of the genus’s bristly seeds.
Its mass flowering has drawn study in Australian urban forestry, both for the biology behind the leaf-drop-plus-bloom strategy and for the public interest the display generates in streets and parks each summer. Studies of its flowering physiology point to the link between a dry spring, leaf drop and the mass bloom, which is why street trees flame in some summers and barely in others.
Uses & Benefits
It is planted in parks, streets and large gardens across Australia and in frost-free places abroad, valued almost entirely for the occasional scarlet spectacle. A mature tree casts deep shade and needs genuine space, so it belongs in the large landscape rather than the small border.
Its relatives’ seeds, the kurrajongs, were roasted and eaten by Aboriginal Australians after careful preparation to remove the irritating hairs, and the water-storing trunks served as a drought resource; this species is grown today almost solely as an ornamental. In Australian parks it is often planted as a companion to jacaranda, so that blue and scarlet alternate down an avenue in the same early-summer weeks.
Growing from Seed
Sand the coat thin, then soak the seed overnight in warm water and sow it in an open mix. Keep the pots warm, bright and evenly moist; germination is erratic and may stretch over several weeks.
Pot the young trees on deep, because they make a root first and a top second, and grow them on in full sun. Plant out only where there is room for twenty metres, and be patient: the flame display comes when the tree is ready, not when the gardener wants it. The bristly hairs on the seed pods irritate skin, so handle the follicles with gloves when collecting or cleaning seed.
Our Take
A tree that saves up for years and then burns the sky red. Give it warmth, deep soil and space, and one early summer it will stop traffic.
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