It is good question since it pertains directly to the City of Santa Barbara's Defensible Space requirements. The Santa Barbara Municipal Code 8.04 specifically states that vegetation must 'not form a means of rapidly transmitting fire from the native growth to any structure'. This is done by removing "fire ladders". (a term used often when referring to defensible space)
Removal of a "fire ladder" is done by separating vegetation both horizontally and vertically. When this happens, it slows the spread and the intensity (heat) of the fire, giving firefighters an increased ability to safely protect your home. Removing fire ladders requires that ground cover vegetation be separated from tree canopies and that there is clearance between shrubs, bushes and trees.
Often times while performing road clearance we come across fire ladders. These are usually the result of unmaintained hedges. Hedges that are maintained with all trees properly limbed several feet above the top of the hedge are all right. However, when the hedge extends into the tree canopy, providing an easy means for a ground fire to quickly climb its' way into the upper portions of the tree canopy, it is not. We do our best to work with homeowners in this case to come up with a win-win solution to providing for both fire safety and privacy.
Above is an example of a major fire ladder in the Eucalyptus Hill area. As you can see the vegetation has not been maintained and there is an easy "route" for the fire to use a mixture of hedge, exotic, native, and flammable material to climb. We worked with the homeowner to come up with a solution. Since most of the "hedges" have become more like trees we could have raised all the bottoms (skirted) of the trees up about 6ft or, like we did, remove the fire ladder by cutting back those portions of the trees that extended into the upper canopies. Now that the vegetation has been cut back, we expect homeowners to maintain the work that has been done so that it does not become a fire hazard again. This helps insure the fire safety of that homeowner, the neighborhood and the community.
