According to Cal Fire, “the purpose [of a Shaded Fuel Break] is to reduce the amount of combustible material so that when a fire hits the shaded fuel break it will decrease in intensity, cool down, and drop from the canopy to the ground. Along roadways, shaded fuel breaks create safer ingress and egress routes for firefighters and citizens.” “Fuel breaks are not designed to stop fire spread, especially during periods of strong winds when fire can be blown across these linear features.”

Shaded Fuel Breaks are typically placed strategically – near residential areas, along key ridges identified by fire agencies, valley bottoms, access roads, or in areas that employ beneficial fires. Shaded fuel breaks often cross jurisdictional lines, so coordination with fire agencies and neighbors is critical.

Generally, a Shaded Fuel Break is not possible in chaparral, unless the shrubs are unusually tall. A fuel break between patches of shrubs can be created, but it will not be shaded.

The width, location, and intensity of a Shaded Fuel Break is best decided by professionals who plan across multiple parcels. Connecting with projects and groups in your community can help you decide how to incorporate shaded fuel breaks into your land stewardship approach. See Resources for Implementing.

When designed and implemented with care (see below), Shaded Fuel Breaks can be less harmful to important ecological functions such as habitat and forage for wildlife, as well as water and soil retention.

It’s very likely that invasive species will establish following treatment, so any Shaded Fuel Break project should have a plan and funding in place to monitor and treat invasives on an ongoing basis, to avoid habitat degradation and loss of fuel break functionality.

If your focus is creating safer use of roads, driveways, or trails, then roadside clearance or fuel reduction of 10 to 15 feet on each side is generally sufficient.

This section is meant to inform your conversations with fire professionals, land use planners, and other professionals. 

Spacing between plants will depend on the plant community, goals and objectives, topography of the site, and whether you want dense shade or are simply breaking up the canopy.

The lower branches of trees are typically limbed or removed to a minimum of six feet from the ground, or the space between surface vegetation and the lowest branches of the tree should be at least three times the height of the vegetation (see photo), to prevent fires climbing into canopies where they can be lethal to trees. 

Grasses, particularly native perennial grasses, should be retained and mowed or grazed to under one foot tall but no shorter than three inches tall, in order to protect the soil, hold it in place, and reduce the opportunity for invasive species such as brooms to establish on open soils.

Woody materials on the ground – such as dead branches, shrubs, downed logs – should be kept to a minimum. Keep in mind that pruning and thinning in the shaded fuel break typically produces a large volume of woody material. Before you begin, you need a strategy for handling cut plant material. See pages on Managing Woody Material, Beneficial Fire, and Pile Burning. 

In remote, steep areas, lop-and-scatter is sometimes the only feasible method. In the short-term, before material begins to decompose, this method will increase surface fuels. Be sure to keep any scattered material at least four feet away from trees to protect them in case of a wildfire.

Timing Considerations 

This practice is best done outside of the bird nesting season, generally from March through August in Sonoma County. This timeframe covers nesting season for the majority of songbirds and raptors (birds of prey). If the work is done during nesting season, consider first conducting Nesting Bird Surveys. Surveying over a longer period can protect more types of birds. For example, the Northern Spotted Owl can begin nesting as early as January in Sonoma County.

Equipment

Personal Protective Equipment (PPE)

• Long pants
• Long-sleeve shirt
• Boots
• Helmet
• Eye protection
• Leather gloves
• Ear protection

Tools

• Chainsaw
• Hand saw
• Pruner
• Loppers
• Pole Saws or a ladder to use with hand tools

Shaded fuel breaks require maintenance and upkeep, typically on a yearly basis at the outset. Annual inspections, especially after heavy wind or winter storms, are important to see if any trees have been damaged or need additional pruning. 

Once cut, most woody species are likely to resprout. (Douglas fir is an exception.) How resprouts are managed is defined by the intended outcome: Do you want this plant in this location? 

• If no, then remove all resprouts. Where manual or mechanical maintenance is not feasible, for very vigorous woody resprouters like eucalyptus, acacia, mature broom, or California bay, you may consider dabbing a small amount of herbicide on fresh-cut stumps, to stop resprouting without causing wider harm. 
• If yes, ask yourself – do dense resprouts pose a problem or risk for this particular location and therefore warrant thinning? 
  • If no, then no action is needed.
  • If yes, then for trees remove all but two or three of the tallest or most vigorous sprouts to accelerate upward growth. For shrubs, generally retaining all resprouts is fine.