Fall 2005

Table of Contents

Wildfire protection can be compatible with wildlife provision

Wildfires spawned by our ongoing drought once again raise a good question:
Can you provide for wildlife, with lots of natural vegetation in your backyard, and protect your home at the same time?

The short answer is “yes.” But there are many conditions to consider and steps to take before you can maintain what fire fighters call a “defensible space” around your home.

First of all, keep in mind that Washington is part of a fire-based ecosystem. Wildfire always has been and always will be a natural part of our ecological history. The key to accepting that is to prepare accordingly.

Two types of wildfires are important to homeowners. Surface fires burn litter and plants, shrubs and small trees and happen naturally every 5-15 years. Crown fires are more destructive, moving through the canopy of a stand of trees, burning from tree crown to tree crown. Historically crown fires did not occur as frequently since surface fires prevented fuels from accumulating, making it harder for flames to reach the crown layer. But with years of fire suppression and debris accumulation, crown fires are more likely now.

To create that “defensible space” around your home, plant and maintain vegetation in several concentric zones within 100-150 feet around structures, with transition areas between zones to slow advancing flames.

The first zone, within at least 10 feet of your house, should be in moist, trim, low-growing plants like mowed lawn, perennials, groundcovers and annuals. Keep this zone well-watered and free of dry litter.

The second zone should be low, sparse, drought-tolerant shrubs and groundcovers. Many native plant species work well here.

The third zone can include thinned trees or shrubs where ground debris is removed and overgrowth trimmed regularly.

The fourth zone, furthest out from your house, can be your “natural area” with selectively thinned trees and shrubs, preferably less fire-prone species.

Property with steep slopes or windswept exposures need greater defense distances. A house at the crest of a hill, with an overhanging wood deck and trees and shrubs close by or below, is at greater risk.

Although all plants will burn if conditions are right, some are more “fire-resistive” than others. These plants naturally have high moisture content, little or no seasonal accumulation of dead vegetation, low volume of total vegetation, non-resinous woody material, open, loose branching, and are drought-tolerant and slow-growing. (See the list of fire-resistive plants, most of which are also good wildlife plants.)

Pyrophytes or “fire-prone” plants that ignite easily or burn intensely should be avoided or minimized, especially close to structures. These plants usually accumulate fine, twiggy, dry material, have leaves or wood with volatile waxes or oils, gummy, resinous sap or leaves with strong odor, loose or papery bark, hair-covered leaves, are blade-leaf or needle-leaf evergreens, or flame (not smolder) when ignited. Junipers and cheatgrass are examples of pyrophytes.

Landscape maintenance for wildfire prevention is different from that for wildlife habitat, but you can compromise by using your zones. To maintain your fire defensible space, you must regularly water, mow, rake, trim, prune, and remove accumulated plant debris – the very stuff that some wildlife species thrive on.

Emphasize this kind of maintenance just in the first few zones closest to your home. Leave your brush piles, understory duff, snags, and other “fuzzy” features of your wildlife sanctuary to the natural area furthest from your home.

Even in your natural area, however, you should reduce or eliminate “ladder fuel” configurations, or vegetation communities structured like the rungs of a ladder – leaves, grasses, small shrubs, brush piles, snags, and trees – to minimize the development of destructive crown fires. Reduce surface fires from climbing into tree crowns by pruning the base of the crown six to 15 feet from the ground. Reduce lateral movement of fire by trimming branches that span between crowns to ten feet or more apart.

Fire really is a natural part of our ecosystem because a vegetative community’s natural way of growing is very fire conducive!

One more thing you can do to prevent wildfire, (or deal with it more easily when it happens), is also something that benefits all wildlife: keep water on your property. A large pond can serve as a firebreak or may come in handy as a water source for fighting fire.