Plants such as eucalypts, melaleucas, callistemons and pines and other conifers contain oils or resins which can burst into flames when heated, increasing the fire intensity. Loose rough bark or bark that hangs in strips from branches is undesirable as it can be a means for fire to climb to tree canopies. Many eucalypts and melaleucas are in this group. Paperbarks, tea-trees and cypress pines often retain many fine dry twigs that can easily ignite. Fire resistance Fire-resistant plants have the ability to survive some exposure to fire.
Fire resistance is quite different from fire retardance.
For example, most eucalypts and paperbarks are highly fire-resistant, and can survive even intense fires, but the high oil content of their leaves and loose bark may cause the fire to intensify rather than be retarded. On the other hand, most rainforest trees are quite fire-retardant because of their high moisture content and low yield of dry fuel. However, many are very susceptible to fire, and may die following exposure to heat from even a mild fire. They are like a one-off insurance policy, and would have to be replaced after an intense fire. The layout of your garden is as important for minimising fire risk as choosing the right plant species.