The Sensitive Edge

In an industry when built and natural environment interfaces are ever converging, responsible and aesthetic landscape design has become one of our most important roles as landscape architects. For example, fire restrictions and protections within ‘High Fire Severity Zones’ at urban-wildland interfaces limit the use of the typical homeowner ornamental plant palettes, flammable structures, and restricts plant placement and tree- to-shrub and shrub-to-shrub spacing surrounding new construction. However, creative design solutions can provide surprisingly innovative and aesthetic designs even in the most restrictive zones that will appease the most aesthetically-minded homeowner.

Newly constructed architectural and landscape structures located within a ‘High Fire Severity Zone’ are required by the City’s Local Fire Authorities to have Fuel Modification planting zones that implement “fire-wise” landscaping principles to better protect homes from wildfires.

Fuel modification zones are designed to limit and reduce the amount of fuel available for a wildfire within a certain distance from a building or structure. Plant palettes developed and approved for use within fuel modifications zones include plants that are high in moisture and low in available combustible or quick-burning fuel which makes them more fire-resistant. Increased spacing is required between plant materials to prevent “fuel ladders” where fire can easily spread from low groundcovers to tree canopies.

Another unique factor to each location is the amount of “fuel” presented by the adjacent natural setting and its accompanying vegetation. Fuel modifications vary in complexity and are designed and developed taking into consideration many factors: topography, degree of exposure, local weather conditions, vegetation, and the design, construction, and placement of structures. Fuel modification zones are no longer limited to adjacent slope conditions. Current development can include entire graded housing lots within a fuel modification zone.

Irrigation is also necessary to maintain moisture within and around the plants to reduce combustible areas. This poses its own challenge as irrigation must comply with the State mandated water use ordinances which, as a result of California’s ongoing drought, became more stringent in 2015 and is updated by region based on current environmental conditions and natural resources. For example, turf is the best fuel modification plant species to use per local fire authorities. Yet, given the strict state water mandates, turf cannot be used in most cases as the water requirements for turf far exceed the allowable water budget when determining water-use calculations based on the state mandates/requirements.

With these plant, water, and plant spacing constraints/requirements in mind, FORMA embraces the challenges and finds it our mission to develop plant palettes and dynamic plant layouts to achieve an aesthetically pleasing landscape environment. Our planting designs incorporate unique structural forms, colors, and blooms of a number of diverse succulents. Their fleshy moisture-laden leaves are naturally fire-retardant and their specimen-like qualities make them perfect for large spacing requirements. In addition, succulents are typically drought tolerant and their low water needs help our designs comply with state water restrictions and mandates.

FORMA successfully designs many large scale community projects requiring approved Fuel Modification Landscape Plans. The following recent successful projects have been designed, approved, and installed: the Four Seasons at Beaumont, Avenswood, Azalea, Wisteria, Tamarind II and Bradford at Rosedale in Azusa, Monterra in Santa Clarita, and Brightwater in Huntington Beach located adjacent to the Bolsa Chica Wetlands.