Controlling wildland fire exposures
The National Fire Protection Association (NFPA) website has excellent articles and information on fire protection and managing fire exposure. Much of the following information comes from their standard, NFPA 1144 – Reducing Structure Ignition Hazards from Wildland Fires.
Fire protection plans should address four zones around a property:
Zone 1: The most immediate zone is the landscape area closest to the building and includes the area encircling the structure for at least 30 feet on all sides. To begin, the planting bed structure should be noncombustible (e.g. stone, gravel, bare ground) or well irrigated if constructed using combustible materials (e.g. bark mulch).
In general, plantings should be carefully spaced, low-growing, low-flammability species, grasses, and lawns. Shrubs planted next to the structure should be of low flammability, no more than 18 inches in height, and not planted directly against the structure. All highly combustible plants, such as junipers and ornamental conifers, should be removed or trimmed and maintained to be ignition resistant.
Regular upkeep is important too. Areas of vegetation such as natural areas, undeveloped areas, landscaped areas, fields, etc. that exist near the structure should be evaluated for the possibility of causing ignition of the structure. Landscape vegetation within 30 feet of structures should be adequately irrigated as needed, cleared of dead vegetation, and/or planted with succulents and other plants that are low in flammability potential. Vegetation deposits (dry leaf and pine litter) that can support surface fire and flames should be removed regularly.
Zone 2: Progressing outward from the structure, the types and densities of vegetation should change to reduce the continuity of vegetation fuels. For example, planting can be done in islands. Trees can be introduced into this zone with careful consideration of their flammability and continued maintenance to separate crowns and avoid ladder fuels. Tree placement should be planned so that the edge of the canopy of the tree when fully mature is no closer than 10 feet to the edge of the structure.
Zone 3: Even farther from the structure, more medium-sized plants and well-spaced trees can be planted in well-spaced groupings to reduce exposure to wildland fire and help maintain privacy. The volume of vegetation (i.e. fuel) should be kept as low as possible or practical.
Zone 4: The most distant area [100-200 feet] from the structure determines the extent of the structure ignition zone. Plants in this furthermost area should be carefully pruned and thinned, and highly flammable vegetation removed. Particular attention should be paid to the types and densities of the vegetation in this area. For example, some vegetation and trees generate more firebrands than others and require additional thinning, removal, or replacement.
The local fire department or authority having jurisdiction for your camp should require you to develop a landscape plan for the property. It is wise to seek their advice and incorporate their recommendations as you develop a plan specific to your location.