12 May-June 2008 Applegater
Maintaining Defensible Space
Is your defensible space alarm clock ringing?
BY SANDY SHAFFER
and resinous. (For more information on fi re-resistant plants, including fl owers, land covers, shrubs
and trees, go to http://extension.oregonstate.edu/deschutes/ or http://rvfpc.com.)
Tip: Your home’s survivability during a wildfi re could depend upon summer
weather patterns! Do you know if afternoon prevailing winds affect your homesite
or property? Find out, and then take more care in thinning outward from your home
in that direction to try and decrease a potential fi re’s spread.
Tip: Your access route could make the difference as to whether your home
survives a wildfi re. Once you’ve thinned per your fi re inspector’s recommendations,
W
hen the Applegate Fire Plan was written in 2002, developing “defensible
space” was one of our primary objectives. Many residents contacted
Fire District #9 or the Oregon Department of Forestry (ODF) for a
home inspection and thinned out vegetation within 100 feet of their homes to
make them more fi re-safe in 2002 and 2003. When did you do your work? Is your
defensible space alarm clock ringing? Depending upon what type of vegetation
you have growing around your home, it may be time to do some maintenance work
right now, before this summer’s Fire Season!
For new residents: Creating defensible space consists of thinning out
vegetation that can carry fi re or burning embers to your home. This usually is
outward at least 100 feet from the house, depending upon slope and vegetation.
Things we usually look at include:
• ladder fuels (that can allow surface fi re to move up into tree crowns)
• tree crown spacing (so that a fi re doesn’t spread from tree to tree as quickly)
• continuous fuels (that lead right up to your home’s siding, outbuildings, decking,
vehicles and other hazards such as propane tanks)
• access and egress (thinned vegetation along your driveway can make a wider
fuel break and allow fi re vehicles to get to your home)
• fuels in contact with the home (trees overhanging the roofl ine, near a chimney,
underneath windows)
• home-building materials and condition
Every homesite is different, so it is important that you have your local
fi re district or someone from the ODF come out and assess your home’s
defensible space needs! (You also can fi nd more information on Defensible Space and the
Home Ignition Zone at http://rvfpc.com or http://fi rewise.org.)
Defensible space maintenance:
Initial thinning around your home can
be a big task, but once you’ve done this,
it doesn’t take more than a few hours
of work each spring to maintain your
defensible space! (Isn’t that a small price
to pay for a more fi re-safe home?) If
you’ve been doing annual maintenance,
you know. Raking fall leaves, spring and
early summer mowing, and some light
pruning might be all you need. But if
you’ve let things go a few years, here are
some tips and a step-by-step way to simplify the process.
Tip: Get to know the characteristics of your native trees. Most have favored
aspects; for example, fi r trees like a cooler northern exposure, while oaks love the
sunny south. What direction does your homesite face?
Oaks, madrone, alder and big-leaf maple will resprout for years after cutting,
so you continually have to cut down the new shoots, which have become ladder
fuels. (This is something that you can use as a management tool—knowing that
you can have a healthy young tree sprout up in a few years! [photo 1]). However,
conifers (fi r, pine and cedar) do not resprout when cut. And did you know that the
hardwoods have been known to slow down a crown fi re because they hold moisture
in their leaves and have fewer oils than conifers? So having a mixed-variety forest
is a good thing.
Tip: Ladder fuels can be tough to fi gure out (photo 2), but knowing a little
about how and why plants burn can help. A general rule of thumb is that fl ames
from plant materials could be about three times the height of the plant. So, six-
inch tall grass could produce up to 18-inch tall fl ames, and a three-foot shrub could
throw fl ames nine feet into the air!
Tip: Use fi re-resistant plants in your landscaping—they don’t readily ignite
from a fl ame or embers, so won’t signifi cantly contribute to the spread of fi re near
your house. The physical characteristics of a plant make them fi re-resistant: moist
supple leaves, little dead wood or needles within the plant, sap is water-like, not thick
walk the driveway each spring looking
for ladder fuels and branches that have
begun to infringe on your access route’s
fuel break, and trim them back. (photo
3). And clean up thick accumulations of
dry leaves along the roadbed to prevent
spot fi res.
Tip: Do you have a refl ective
address sign at the street and at every split
in your driveway? Refl ective signs will
show up at night or when visibility is low (photo 4). Make sure your signs are well-
placed and visible! (This also could mean valuable minutes saved in a life-threatening
emergency!) The fi rst address sign is free from Fire District #9.
Tip: Maintaining your defensible space isn’t just about vegetation—it also
includes general cleanup around your homesite, removing debris and trash, repairing
damaged roofi ng, etc. It’s easier to catch everything if you follow a routine, looking at
your property at several scales and heights rather than the front, side or back yards.
An assessment system of fi ve simple steps (or zones) has been developed by wildfi re
behavior experts to measure a home’s ignitability and fi re preparedness, and I think
they also work very well when considering what maintenance you need to do on
your defensible space. Below I’ve listed the fi ve zones and then applied things to
look for within each one during an annual maintenance check. (Note: this approach is not
See DEFENSIBLE, page 13