Bottle Tree, Leaf Drop and Sun Damage

Bottle trees (Brachychiton populneus and locally called Kurrajong) are Australian native trees found in the northern tropical and subtropical climates there. They are classified as “drought deciduous”. Drought deciduous just means they start dropping leaves when the soil gets dry from September through December every year. For B. populneus the swollen roots are thought to store water for dry periods.

The other common Bottle Tree, (Brachychiton rupestis), does this as well and has a trunk with more of the traditional "bottle" shape. Both grow too tall and large for most home landscapes. They can be grown in lawns if not overwatered and you make sure the soil will drain fast. If these trees are watered too often or the soil does not drain well, the roots of the trees can suffocate and the trees die.

Bottle tree with horizontal limbs and thin bark gets sun damage and can drop its leaves if the damage is severe. This tree has thin bark that should be protected from intense sunlight and vandals.

They are thought of as "desert trees" but they aren't. The intense sunlight of the desert can burn their horizontal limbs and, if enough damage is done by the sun, the leaves will drop.