If you live in an area at risk for wildfires—like Southern California or much of the West—you may have heard of certain plants that are fire-resistant. It makes sense to take measures to landscape your property with shrubs, trees, perennials, and succulents that may, in some cases, possibly save your house from burning down. But what about the most flammable plants—the ones you should consider removing or at least not planting? These plants are known for the amount of dead fuel that accumulates inside them, high oil (or high resin), or the low moisture content of their leaves and branches. Characteristics of highly flammable plants include:
Dry and dead leaves or twigsDry, leathery leavesAbundant, dense foliageHigh oil or resin including gums or terpenesShaggy, rough, or peeling barkLots of dead leaves underneath the plant (litter)Needle-like or very fine leavesFoliage with low moisture
The following list of flammable plants was created from information provided by various fire agencies, and botanical organizations throughout the United States. They are presented in alphabetical order.
Arizona cypress (cupressus glabra) Italian cypress (cupressus sempervirens) Leyland cypress (cupressocyparis leylandii) Tecate cypress (cupressus forbesii)
While these evergreen trees are useful as screens, hedges or windbreaks, they are strongly scented and can become tall torches during wildfires. Several varieties contain highly flammable resins. Junipers can accumulate dead leaves, and as they age, they become more prone to easily ignite. Some firefighters nickname them “gasoline plants”.
Dried and dead palm fronds become like flaming arrows if they detach from their trunks and are carried by winds.Embers can become embedded into the fibrous tissue, leaf bases, or along the trunk of a palm tree. The result: a palm that can rapidly become engulfed in flames, spreading to other plants and structures nearby.
Certain species of palm trees can be hazardous in fire-prone regions, especially if they are not maintained (pruned) or because of their form. Palms with fibrous tissue or leaf stem bases along the trunk should be 30 or more feet from a home or structure.
Species to Avoid
Mediterranean fan palm: Chamaerops humilis Canary Island date palm: Phoenix canariensis Date palm: P.dactylifera Senegal date palm: P. reclinata Pygmy date palm: P. roebelenii Windmill palm: Trachycarpus fortuneii Mexican fan palm: Washingtonia robusta, has a leaf stem base that makes it catch fire and spread quickly.
