Fire-Hazardous Plant Characteristics
Source: Sustainable Defensible Space
Certain plant characteristics make vegetation more vulnerable to ignition and flame spread, especially when drought-stressed or poorly maintained. Any plant with poor health, lack of irrigation, or accumulated dry material can pose a fire hazard. Common high-risk traits include:
Summer dormancy without irrigation (e.g., sagebrush, sages).
Dry leaf litter and duff buildup on the ground or nearby plants.
Dry, peeling bark on trees and shrubs.
Retention of dead leaves, branches, or fronds (e.g., palms, eucalyptus, Italian cypress).
Seasonal dry grasses that turn yellow/brown in summer.
Key Traits of Trees Prone to Ember Ignition:
In other words, essentially, we’re looking to explicitly protect against trees that could be ignited by embers contacting their canopy (for these cases, we have no way of protecting the house from these trees, if they are in close proximity). Trees with the following characteristics are most at risk of direct canopy ignition from embers:
High resin or oil content in wood or foliage.
Dense, fine foliage that traps embers.
Shredding or peeling bark that ignites easily.
Dead material (e.g., palm skirts, dry branches) in the canopy.
Trees with these traits near structures pose a severe ember ignition risk and are difficult to defend against.
Fire-Hazardous Plant List
We maintain a growing list of fire-hazardous plants and their associated thermal loads to use in our physics models. If you are interested in hearing more, please contact support@standinsurance.com
