Crown fires move through the tops of trees and are hardest to stop
A surface fire burns through grass, leaves and small shrubs on the forest floor. A crown fire is what you get when that surface fire climbs into the...
A surface fire burns through grass, leaves and small shrubs on the forest floor. A crown fire is what you get when that surface fire climbs into the canopy and then propagates from treetop to treetop, often well ahead of the surface flame below. Crown fires are the most dangerous form of wildfire behaviour because they move fast, are nearly impossible to attack directly with ground crews, and throw embers great distances. The fuel ladder that lets a surface fire climb into the canopy is exactly what FireSmart and Firewise USA target when they tell homeowners to prune lower branches up at least two metres (about six feet) from the ground and space crowns at least three metres (about ten feet) apart in the extended zone. A well-spaced, well-pruned forest can drop a crown fire back to the surface, where crews can fight it. Around your property, the same principles apply: do not let dense, untended evergreen stands run right up to the house, and pay particular attention to ladder fuels — small trees and shrubs growing under bigger trees.
A crown fire moves through the tops of trees, often far ahead of the flames on the ground — once a fire reaches the canopy, ground crews can rarely attack it directly.
Source: FireSmart BC — Home Ignition Zone
Last reviewed 2026-05-02.
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