Wildfire season has finally slowed but, like it or not, now is the time to start getting your property ready for the 2019 fire season.
You may remember from the last Wildfire Corner that the HIZ, also known as the Home Ignition Zone, is composed of three smaller zones:
Zone 1: The Immediate Zone (AKA Be Ember Aware): Distance 0 – 5 feet
Zone 2: The Intermediate Zone (AKA Lean, Clean and Green): Distance 5 – 30 feet
Zone 3: The Extended Zone (AKA Reduce the Intensity): Distance 30 to 300 feet
In the summer edition of Stewardship Notes we focused on Zone 1 – Be Ember Aware. In this edition we will focus on Zone 3 – Reduce the Intensity Zone (keep an eye out for Zone 2 in the spring!). 
Zone 3 is the area outside of your yard and garden, most of us would call it our woods or forest. This zone can extend up to 300 feet from the structure you are working around. The goal in Zone 3 is to reduce the intensity of wildfire. Instead of having 20 or 30-foot flames going through your property, we want much smaller flame lengths. These smaller flames reduce the damage to your property and make firefighting resources more effective.
To accomplish this, we need to work on reducing the amount of fuel that can cause large flames. Typically what gives us the large flames in a wildfire are trees. So this article focuses largely on thinning the forest in your third zone. Check out the Stewardship Notes article from August 2016 to learn about all of the benefits of forest thinning (besides wildfire protection).
From a fire perspective, we are trying to thin trees to get what we call “roads in the sky”. Roads on the ground often act as a fire break by slowing or stopping fire spread, but we also want these fire breaks in our tree tops. When you look up into your trees you should see a minimum of 5-6 feet between the tips of the tree branches. This creates fire breaks in the sky to reduce the chance of tree-to-tree ignition. Further spacing is recommended on steep slopes and as you get closer your house.
If you prefer, you can leave small clumps of trees as you thin your forest, but be sure to isolate those tree clumps from surrounding trees and other clumps you may create. People will often leave these for wildlife or aesthetic values. Check out this article to learn how to conduct a wildlife friendly fuel reduction project.
Once you have thinned your trees the next step is to remove “ladder fuels”. Ladder fuels carry fire into your tree canopy from the ground. A tree with branches that start at the ground and reach up to the canopy create a “ladder” of fuel that can carry flames from the bottom to the top. Ladder fuels can also occur when you have grasses or brush in contact with low branches.
To eliminate this ladder we recommend pruning the branches off of your trees. It is recommended to prune them up to ten feet, but never more than half the tree (so if you have a 12-foot tall tree, you only prune up to six feet). This is to maintain a healthy living crown in the tree. Disposing of the pruning slash is an important next step. Most homeowners will burn it in piles or chip the material. The September 2017 Stewardship Notes has an excellent article on burning piles. However, either method will help reduce fuels on the ground and the height of flames, were a wildfire to occur. If you decide to chip, the material should be piled or scattered. When scattering, keep chip depth less than six inches, preferably less than three inches where possible. See the April 2018 Stewardship Notes article about chipping.
Enjoy the nice fall weather and start thinning some of your trees to be ready for the 2019 fire season. Keep an eye out for the Spring Stewardship Notes edition for the final article in this series covering Zone 2. As always, for more information on preparing your home for wildfire, check out the National Fire Protection Association website.
By Guy Gifford, landowner assistance forester & fire prevention and Firewise coordinator, Washington State Department of Natural Resources, Northeast Region, guy.gifford@dnr.wa.gov
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