Home Ignition Zone and Landscape Zones in a Firewise Landscape

The Home Ignition Zone begins with at least 30 feet of defensible space immediately around the home and extends out as far as 100 to 200 feet depending on the characteristics of adjacent lands (Be Firewise Around Your Home, FWC-100-06). Creating and maintaining the Home Ignition Zone reduces or eliminates ignition hazards. Within the Home Ignition Zone, a Firewise landscape can be created by reducing fuels. The best way to do this is to establish landscape zones that start at the home and move progressively outward.  These Landscape Zones (LZ) within the Home Ignition Zone should be used when selecting vegetation on sites that have a high fire risk.

There are essentially three Firewise Landscape Zones:

Landscape Zone 1 is closest to the home, while Landscape Zones 2 and 3 subsequently extend out from the structure. Unofficially, there is a Zone 4, which is the surrounding natural vegetation that is usually beyond 30 feet from the structure. The Fire Performance Plant Selector makes recommendations for selecting vegetation only within the portion of the Home Ignition Zone that extends 30 feet from the structure. Within this Home Ignition Zone of 30 feet the Fire Performance Plant Selector makes recommendations on plant material for Landscape Zones 1, 2 and 3.  The Fire Performance Plant Selector makes recommendation for the first 30 feet of the Home ignition Zone which typically extends out 100 to 200 feet from structures.

You may download a PDF of this landscape zone illustration here.

Landscape Zone Descriptions:

Landscape Zone 1, (LZ1), is the area 5 feet out from the home or structure. Nothing flammable should be planted or placed against the structure. This includes trees, brush, tall grass, leaves, firewood piles, bark mulch, and other flammable materials. Carefully examine under decks and in dense vegetation for accumulated dead material and debris. Prune trees that have branches and foliage that hangs within Landscape Zone 1 to eliminate possible fire transfer up exisiting trees, into the branches, and onto the structure, a concept known as the “ladder effect.” Within this zone, low-flammable plants can be planted if they are maintained properly for Firewise conditions.

Landscape Zone 2, (LZ2), is the area 5 to 10 feet from the house or structure. Maintain a well-kept lawn in this area and avoid evergreens that can ignite easily and burn quickly. Use raised beds, rock gardens, stone walkways, walls, and patios to create visual interest while creating fuel breaks. Trees planted in LZ2 should have both a vertical and horizontal clearance distance of at least 10 feet from the house or structure at mature height. Leave 10 to 15 feet of space between the edges of tree crowns to avoid fire transfer.

Landscape Zone 3, (LZ3), is the area 10 to 30 feet from the house. Remove yard debris and thin vegetation for a distance of 30 feet away from the house or structure. Driveways within LZ3 can provide a fire break. On a slope, one should extend clearing and thinning out of vegetation to 100 feet on the downhill side. Shrubs and groundcovers should be selected based on mature height, not the size at the time of planting. Low and moderately flammable plants are acceptable in this location. Massing of plant material should also be minimized. Brush and weeds should be mowed annually. Terracing of steep slopes will help slow wildfire spread but this depends on wind speed and fuel availability. Trees in LZ3 should have a minimum of 10 to 15 feet of space between tree crowns to prevent the spread of fire to other tree  crowns.

Landscape Zone 4, (LZ4), is any area beyond 30 feet beyond the structure and can extend to 200 feet from the house or structure. Homeowners should be aware that it is relatively common that land adjacent to their properties may be prone to wildfire. The Fire Performance Plant Selector does not address the area beyond 30 feet from a structure. Within LZ4, more flammable plants can be planted, although cultural and Firewise recommendations on vegetation care, pruning, and maintenance are still relevant.

Since no plant is completely non-ignitable or nonflammable, there is not a category for Fire Resistant Plants, however, low-flammable plants, if maintained properly, can be used to landscape around a home within Landscape Zones 1, 2, and 3.