Landscape Design for Defensible Space in Fires

The role of landscaping as a way to help preserve Oakmont in the face of another catastrophic fire has been the subject of great discussion in Oakmont, prompting an invitation to UC Extension Master Gardeners Linda King and Mary Lou Milkoff to talk to directors of homeowner associations about Firewise Home Landscaping.

Also at the Sept. 5 meeting were members of the Oakmont Fire Safety Committee, OVA Board President Steve Spanier and General Manager Kevin Hubred.

“The ‘New Normal’ for fire safe landscape design has really changed since the Tubbs

Mary Lou Milkoff, left, and Linda King talk to LOMAA members. (Photo by Marlena Cannon)

fire,” King said. “Instead of two zones of defense around the house, latest fire data has shown the need for three.”

Zone 1 is the Ignition Zone, from zero to five feet from the house and is the most critical. It should contain no combustible or flammable material, including mulch or fencing; plants measuring no taller than two feet tall and that are herbaceous perennials or succulents; and, roofs and eaves that are free of tree limbs or vines.

Zone 2, the Firebreak Zone, is between five feet and 30 feet from the house and should include ‘plant islands’ that are widely spaced and surrounded by hardscaping elements such as pavers and/or a non-flammable ground covering material. Tree limbs should be three times higher than underplanted shrubs and all plants should be trimmed of dry leaves or branches.

Zone 3 is the Reduced Fuel Zone and is from 30 to 50 feet and is intended to slow and reduce fire intensity. Grass should be mowed to 4 inches or less; dead branches, old mulch and leaves should be cleared and, trees and plants should be spaced 10 feet apart.

Eight scalable landscape design templates that adhere to the three fire zones can be found at

Mary Lou Milkoff’s home near Fountain Grove was the only one in her neighborhood to survive. She recommends plants that have a high moisture content; produce little dead material; have open branching habits; have broad leaves and are non-resinous.

“Most mulching materials burn fast or can smolder overnight,” she said. “A study tested eight different mulches and showed that composted wood chips were the best but that is very difficult to find. I recommend using compost which is  available at several stores in the area,” Milkoff said.

For information on specific plants that are fire resistant go to the CalFire website at That site also provides tips on ‘home hardening’ to make the homes more fire and ember resistant.

For LOMAA and Oakmont residents, the transition to firewise landscapes will be gradual and ultimately create a new look for the community that is both safe and beautiful.