Defensible Space.
How to create a fire-smart perimeter.
Defensible space landscape design is based on a simple, repeatable concept we call the Five–Six Rule. This method uses distance, materials, plant selection, and canopy structure to interrupt fire behavior while preserving beauty, shade, and a sense of place.
The most resilient properties don’t rely on a single design tactic. They combine fire-smart perimeter design, noncombustible hardscaping, and well-maintained tree canopies into a layered system that works together when it matters most.
The Five-Six Rule
The Five–Six Rule is a simple spatial guideline that turns fire science into good garden design. It’s about shaping the ground plane and the canopy together—creating calm, breathable space around the home that slows fire and elevates the landscape.
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Five feet at the ground: Maintain a continuous band of noncombustible surface around the home—stone, gravel, pavers, or masonry—to interrupt ember ignition and visually anchor the architecture.​ These spaces offer
Six feet in the air: Keep tree limbs and canopy edges at least six feet away from roofs, walls, decks, and chimneys, shaping trees to reduce radiant heat and eliminate vertical fuel paths.
Design, not removal: This approach favors material choice, spacing, and pruning over clearing—resulting in landscapes that feel intentional, shaded, and livable rather than stripped. Together, these two dimensions (the horizontal and the vertical) create a clear, legible perimeter that protects the structure while still allowing the garden to unfold beyond it.
Why the Five–Six Rule Works
The Five–Six Rule draws directly from decades of wildfire research showing that embers and radiant heat, not walls of flame, are the primary causes of home loss.
The resources in the Deep Dive section explain the science behind the approach and offer practical guidance for homeowners, designers, and planners. These downloadable pdf brochures provide design information about creating beautiful fire-resistant landscaping.
Deep Dive
Sustainable Defensible Space
Sustainable Defensible Space is the area focusing on the first 100 feet around your home. It aims to increase resistance of structures to wildfire, safeguard firefighters’ lives, improve conservation values, and protect California’s natural heritage.
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Living with Fire – University of Nevada Cooperative Extension
Living with Fire translates fire science into practical, visual defensible space guidance for people living in fire-prone areas.
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CAL FIRE – Defensible Space Guidelines
California’s foundational guidance on vegetation management and the critical importance of the first few feet around a structure.
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UC Berkeley’s Institute of Urban and Regional Development
A recent Cal landscape wildfire prepared design contest offers innovative ideas for homeowners for creating beautiful, fire-safe landscaping.
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California Office of Emergency Services – Tree & Plant Spacing
Real-world guidance on canopy separation, pruning heights, and reducing ladder fuels. Defensible space, coupled with home hardening, is essential to improve your home’s chance of surviving a wildfire.
U.S. Department of Energy – Defensible Space for Protection Against Wildfires
A practical guide to combining hardscape, spacing, and vegetation management into a cohesive system.
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