Read an Excerpt
THE ZONE THEORY
In the middle of a murky landscape stands a lone house. Its walls are a grayish, sticky black, and the ground cover of periwinkle and iris is singed and curled but still green. All surrounding shrubs are ash. The horizon is torn by jet-black, leafless trees. Chimneys and large piles of soot are seen in the distance, the only remains of the neighbors’ houses.
The scene described above accompanies almost every fire. In the midst of a charred landscape sits a single home, somehow protected from the fire that consumed all others. This chapter emphasizes the reasons why some houses are able to survive. It is a model from which all landscapes should be designed.
Firescaping’s Zone Theory differs from the standard model by addressing the elements that create a beautiful and functional landscape as well as a fire-protected property. Planting for a sense of privacy or holding a hill can unintentionally create a lot of fuel. A good landscape design will not only help defend a home against the threat of fire, but will serve the unique goals of the individuals who care for it as well.
The Zone Theory is perfectly suited for large properties. People who manage small lots, properties on steep slopes, and houses nestled under a grove of trees may find the model cumbersome. Chapter 10 covers slopes; Chapter 11 covers small properties; and Chapter 12 covers ridgetop and understory properties.
ZONE 1: THE GARDEN ZONE/DEFENSIBLE SPACE
Distance: Extends 30 feet from all sides of a house or structure.
Primary goal: The garden zone/defensible space is the most important zone in this model. Without igniting, this zone must be able to withstand firebrands and intense heat, between 900°F and 1,300°F. Everybody and anybody should be able to move unencumbered and swiftly through the garden zone. Firefighters will battle a blaze within these first 30 feet.
Secondary goals: The garden zone has to maintain high recreational, functional, and/or economic value to remain useful to its occupants. The ideals of beauty and privacy play a large role in determining plant selection. Fences, hedges, sheds, compost areas, and stored items, such as firewood, are common in this zone and add a lot of fuel.
RECOMMENDATIONS
PLANT SELECTION Plants in the garden zone must wilt and sizzle, but not ignite, when exposed to flames and heat. This means that plants in this zone will likely be broad-leaved, supple, and moist. This group is considered fire retardant. Chapter 13 (“Plant Selection and Fire Protection”) has Zone 1 plant lists for lawn alternatives, festive perennials, and accent trees.
CARE AND MAINTENANCE The garden zone will consume a disproportionate amount of a landscape’s budget. And rightly so—lives are at stake within this zone. The garden zone also consumes the most water, resources, and time. The most fire-retardant plants will require irrigation and attention, more so in arid environments. Food crops, lush understory plantings, and tropical plantings are some examples of high-maintenance plants that survive firebrands and intense heat.
ACCESS AND ESCAPE The garden zone is where firefighters will fight a fire, so wide, stable pathways must surround the entire structure. There should be a place to stage equipment and people, and clear sight lines to escape routes and the surrounding landscape. Everyone should be able to move through this zone with ease, never worrying about ducking, tripping, or getting entangled. On large lots, it is essential to have and maintain two ways off the property. Refer to Chapter 14 (“Landscape Features”) for more on paths.
GARDEN FEATURES The garden zone may contain a lot of ignitable features: fences, furniture, play structures, shade structures, and storage sheds are common. Naturally, using noncombustible materials, such as metal, is the surest strategy. But there are other strategies too. Refer to Chapter 14 (“Landscape Features”) for more detail.
SOURCES OF IGNITION Many places in the garden zone are likely to produce sparks and flames. Barbecues, fire pits, and work areas need to be designed to handle the occasional spark: flammable vegetation must be cleared around them; Zone 1 plants used; and dead, dying, and diseased vegetation constantly removed.
MAINTENANCE Maintenance is the fulcrum of fire protection. Fire must not be allowed in the garden zone, and the role of maintenance cannot be stressed enough. Refer to the maintenance chapters (Chapters 16–18) for priorities, techniques, and timing of maintenance tasks.
RVS AND TRAILERS
RVs and trailers can be a huge liability during a wildfire: once they ignite, they are incredibly difficult to extinguish. They catch firebrands with canvas contraptions, leafy debris underneath, and openings in paneling and compartments, and they propel a fire with rubber, thin paneling, and stored fuel.
RVs and trailers can be protected:
- Remove awnings and other firebrand-catching appendages.
- Blow or sweep debris from underneath the vehicle.
- Remove flammable vegetation at least 10 feet around the vehicle.
- Install curtains that can deflect heat on all windows.
ZONE 2: THE GREENBELT/FUEL BREAK
Distance: 31–70 feet from a protected structure. Houses on slopes need to add 10 feet to this zone for every 10% increase in slope. For example, the greenbelt would extend to 120 feet on a property that has a 50% slope.
Primary goal: The greenbelt should stop a ground fire. Select low-growing, hearty, and water-thrifty plants. These plants are the most fire resistant. The effects of droughts, freezes, and occupant neglect should have the least impact in this zone.
Secondary goals: Within view of a house, privacy, aesthetics, and wind protection play important roles in plant selection and placement. These goals add a lot of fuel to this zone over time. On sloping properties, controlling erosion is one of the most important roles of this zone....
