Grown successfully in USDA Zone: 9-11, the Brachychiton populneus (Bottle Tree) is a plant native to Eastern Australia. It can be used for bonsai, as it is a big tree, growing taller than 20 feet, and has attractive lobed leaves. The trunk is commonly swollen, as well as the taproot, giving an interesting bottle-like look to the tree. In addition to its aesthetic appeal, this species develops white or off-white, bell-shaped flowers with inner tubes that are streaked with purple-brown. Some hybrids can present pink or red blooms. The fruit of the Bottle Tree are woody and boat-shaped, surrounded by fine hairs that can cause skin and eye irritation, so care must be taken with them.
The Bottle Tree is an evergreen species and does best when grown in full sun, however it also tolerates some shade. It requires regular watering, but is quite resilient and tolerant of dry conditions. It is also easy to propagate from seed or from cuttings from desirable plants which can be grafted onto seedling rootstock. The transplantation must be done with care, protecting the swollen taproot from damage.
In cold regions, the Bottle Tree must be potted and taken inside during cold months. It is mature plant cold hardy at least to 30s F for a short time. The foliage is glossy-green and dense, making it a good option for street trees and to create shade as well as to provide a source of food for animals. The gum exudate is edible, and the swelled, carrot-like taproot is a nutritious vegetable. The species is also attractive to butterflies and hummingbirds, making it a nicely multi-functional plant.