Why are fire-resistant privacy screening plants so important?
Vegetation between houses can either add fuel to the flames during a wildfire or help to slow fire spread.
When highly flammable plants like Leyland cypress, arborvitae, junipers or Italian cypress are used for privacy screening, they can ignite easily, burn intensely and quickly spread fire to your home or between structures. It is a primary reason the Prohibited Flammable Plant List was created; to help prevent homes from catching on fire during ember intrusion events from a nearby wildfire and to help prevent conflagration between homes in the case that a fire starts near a home.
Because fire-resistant plants are more difficult to ignite and burn, they are recommended for privacy screenings between homes.
The 2012 OSU Extension Publication "Fire Resistant Shrubs and Trees for Privacy in Southwestern Oregon" contains suggestions for shrubs and trees recommended for privacy plantings that meet a variety of growing conditions and requirements. This publication provides examples of fire-resistant shrubs and trees that can be used to create a more fire-safe home landscape while providing the privacy you desire.
Excerpts from the above publication:
Highly flammable plants have:
Fire-resistant plants have:
Fire-resistant does not mean fire proof! Even fire-resistant plants that are not well maintained can burn. Be sure to keep all of your landscape plants healthy with appropriate watering, pruning, etc.
Maintenance is Critical. As with any fire-resistant landscaping, maintenance is critical. Deep watering, mulching, and the removal of deadwood and leaves help to maintain the overall health of the plant, thereby reducing the flammability of the overall landscape.
Planting the appropriate shrub or tree in the right place can make all the difference in its long term health and vigor. Keep in mind that heavy shearing or pruning may promote a dense outer crown, resulting in less sunlight reaching the interior of the hedge and causing dieback of twigs. This dieback will create flammable material in the center of even healthy, well spaced shrubs and trees.
Ongoing maintenance is critical for fire-resistant landscapes of all kinds:
Row of burned leyland cypress that contributed to conflagration, Oak Knoll Fire, August, 2010 (Photo by Ali True).
Partial row of Leyland's burned along the fenceline during Chitwood Park fire, August, 2006. The burning Leylands produced enough intense heat it broke the windows of the adjacent home. Luckily, this home had double-paned windows and only the outer panes broke, keeping embers, heat and smoke from entering the home (Photos by Marguerite Hickman).
An arborvitae screen caught fire in 2013 and charred the carport and side of this home. Luckily it was put out quickly before the house became engulfed, but still caused significant damage to the structures.