Rebuilding Landscapes After A Wild West Fire Season
Author: Chad Kennedy, Landscape Architect
For years, the entire Country struggled as they watched the impact of severe drought on California and everyone who calls it home. The next wave of natural disaster to hit, and only one year later for that matter, is unimaginable in scale and devastation. California was literally burned up this year as unprecedented wildfires blazed through over 1.3 million acres of precious California landscape, devouring over 10,000 structures along the way. Children all across the state were restricted indoors during school hours, as most of California was subjected to smoke and unhealthy air conditions despite geographic distances between the nearly 9,000 different fires recorded. The impacts are widespread, and will be felt for years as families, businesses and governments begin to pick up the pieces and rebuild what was lost. Moving forward, it is crucial to glean lessons from the past year's events on how fires were able to spread through entire cities and towns with little resistance. The role of the landscape in these events is fundamental and needs to be looked at very closely as communities rebuild, and as others fortify their defenses against future wildfires. The following is a synopsis on landscape features that are important in building a landscape that acts as a defense against fire and not as fodder.
Landscape Clearances & Fire Zones - Fire officials suggest that the best defense against losing structures to wildfire is to plan for an area, between 30-100 feet surrounding a home or structure, to be clear of trees and readily flammable plant material. As many times structures are closer than 30' to the property line, the property line often becomes the edge of this clear area. This area can be further defined by dividing it into three zones, the 30' zone, the 30'-70' zone, and the periphery zone. The 30' zone should contain low, well-manicured plants that are slow to ignite and that create as little heat as possible (no pyrophytic plants). Higher water use in this area is appropriate if maintenance to limit litter build-up is performed. Parcels of land with structures less than 30' from property lines will fall only within this fire zone.
The 30'-70' fire zone is a transition zone between the periphery and the 30' manicured zone. Plants within this zone should be chosen for ease of maintenance related to litter. They should always be thinned and maintained to remove deadwood and extra fire fuel. Plants should be organized to create well spaced groups that would minimize fire spread. Allow for 30' between tree clusters and 20' between individual trees. Again, low spreading plants and limited trees are preferable.
The periphery zone is typically the fringe of an open space, wildland, or riparian corridor. These areas should be maintained to minimize ground level fuel buildup and should have well spaced vegetation pockets (mosaics) to create natural breaks in fire succession. Tree canopies should not touch each other. The steeper the slopes in these areas, the wider apart these vegetation pockets should be, and the more often the litter should be managed.
Alternative Materials - One lesson that can be learned from the great drought experienced in California is that landscapes can be beautifully designed with materials other than live plants. The use of inert or low flammable materials can create amazing design opportunities and act as fire breaks as well. Plants and flammable mulches can be replaced with planters, walkways, and decks made of cobble, boulders, concrete, pavers, glass or rubber mulch, artificial grass, plastic lumber, decomposed granite, or any number of other materials commercially available. These materials are particularly important within the 30' fire zone as a final fire break between the landscape and structure. As an added benefit these materials do not require irrigation and will limit the amount of water used within the landscape.
Plants - All the appropriate considerations for plant selections still apply to a fire-wise landscape (sun aspect, water requirements, soil pH and fertility, size, etc.). An extra level of scrutiny, however, is imperative when selecting plants that will fight for you rather than against you in the event of fire. In general, the following plant criteria are ultra-important when fire is a concern:
- Litter generation
- Height of plants at maturity
- Amount of plant material that can burn (low growing plants have less to burn)
- Flammability (plants low in oils and resins - non-pyrophytic)
- Longevity - plants that die become fire fuel
In general, plants that are thick, succulent, and leathery are more difficult to ignite. Trees, like conifers that store large volumes of needles, and litter should be avoided. For a comprehensive list of fire resistant plants that may be a first step in planning a landscape click this link to download a booklet prepared by Pacific Northwest Extension. It is important to remember however, that plants can be resistant to fire, but that doesn't mean that they are "fire proof."
Maintenance cannot be overlooked during the process of rebuilding. Though low maintenance options can be designed into a project, there will ALWAYS need to be attention given to limit the amount of litter and growth within the landscape. The following are a few maintenance ideas to ensure that your landscape is fighting as hard for you, in the event of a fire, as you hope it will.
There are many steps that can be taken to fortify a home or structure from devastating wildfires. Though this article focused mainly on landscape options, there are a great deal of structural options that should be looked at in order to holistically approach fire protection. As California communities rebuild in the following years, these principals will become a primary focus, just as water conservation has become commonplace in California vernacular.
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- Mow lawns regularly.
- Remove all dry litter and dead plants from around structures.
- Inspect trees regularly for dead wood.
- Prune trees to between 6'-10' above the ground.
- If the structure has raised decks or patios, remove any weeds of plants from underneath them.
- Maintain regular irrigation to train deep roots in plants and to keep moisture in the soil.
- Do not store firewood or flammable gasses and liquids near the structure.
- Maintain inert fire breaks, such as walkways, cobble, and gravel beds, free of weeds and plant growth.
- Prune trees so there are no branches hanging over structures.
- Prune shrubs so they do not grow under structural overhangs.
- Maintain groundcovers so they stay low to the ground and older woody growth does not build up.
- Keep irrigation systems in working order to avoid dry areas of the landscape.
- Remove self-starter plants and trees regularly to avoid build-up of fuel.