Like many plants native to fire-prone regions, eucalyptus trees are adapted to survive or even thrive in a wildfire.
The leaf litter from eucalyptus trees is full of toxic napalm that bugs and fungus don’t break it down – it just dries out and covers the ground like a super-flammable carpet. Additionally, the eucalyptus oil that gives the trees their characteristic spicy fragrance is a flammable oil: This oil, combined with leaf litter and peeling bark during periods of dry, windy weather, can turn a small ground fire into a terrifying, explosive firestorm in a matter of minutes.
After a bushfire sweeps through an area, the eucalyptus trees have an advantage over other plants. Their seed capsules open up when burned and the seedlings thrive in freshly burned, ash-rich soils.
The California Invasive Plant Council (Cal-IPC) considers the eucalyptus a moderately serious problem, considering its rapid spread and its ability to displace native plant and animal communities.