Fire is as much a part of the Western landscape as oaks on a golden hillside or waves foaming at the rocky shore. Fire has dictated the distribution of the native landscapes that we so love, and molded the evolution of our most distinctive species, from the frothy blue blossoms of ceanothus to the thick, fibrous-barked redwood. But now, when fire ranges freely through the landscape, our homes and communities lay in its path, and disaster often results. Carefully planned gardens can, however, help defend our homes when fire approaches.
The idea of a fire-safe landscape does not have to run counter to that of an aesthetically pleasing garden. In fact, the plant choices and the concepts employed to create a fire-safe garden go hand-in-hand with sustainability, drought tolerance, and a satisfyingly diverse and colorful garden design.
I am a gardener first and a firefighter second, but it is the contemplation of both ideals that helps me design and grow a beautiful, fire-safe garden. To ally your interests with those of the fireman, the key concept is defensible space. Just as an aloe’s red flower attracts the hummingbird, a red fire engine is attracted to safe, open areas to stage and defend a home against flames and sparks. In California, defensible space is one hundred feet of clearance around your home, divided into two sections: thirty feet of a Lean, Clean, and Green Garden Zone against the house, and seventy feet of open Transition Zone beyond.
The Garden Zone needs to be Lean: open and accessible with few obstructions; Clean: kept maintained and tidy without masses of dead leaves, brush, or dry weeds; and (most importantly) Green: full of healthy, actively growing plants that are irrigated regularly. The plants that are best for the Lean, Clean, and Green zone closest to the house are actually the most popular garden plants today: flowering perennials, roses, and edible plants.
But why these particular plants, or other alternatives like them? The reason is simple: they actively grow during the West’s normal fire season in summer and fall, so they will have healthy, soft foliage and will not develop masses of dry woody growth. When a fire comes, they are unlikely to burn, but may simply wilt.
An Approach to the Ideal
The ideal fire-safe garden would include a wide paved path welcoming visitors to the front door, perhaps with a patio on which guests could linger at evening. An appealing combination is a fragrant thyme growing between golden Arizona flagstones. A low seat wall scattered with colorful, weather resistant cushions takes the place of flammable teak garden furniture and keeps the area close to the house uncluttered. Shrubs are kept away from the house walls, but, at the door, a cluster of glazed ceramic pots overflow with succulent Echeveria, Dudleya, Aeonium, and Sedum. Behind them, a fire resistant evergreen is espaliered on a metal trellis that breaks up the expanse of fire-resistant stone facing; Sasanqua camellia, aided by drip irrigation, would be an apt choice. Beyond the low wall, garden beds are arranged casually among native boulders, and a dry streambed glows with the iridescent blooms of a reliable succulent groundcover, such as purple iceplant (Delosperma cooperi).
In summer, I would suggest masses of yellow ‘Sunray’ coreopsis, the native blue foothill penstemon (Penstemon heterophyllus), an ornamental oregano (Origanum laevigatum), and purple ‘Homestead’ verbena to catch the eye. Imagine English roses, like the golden ‘Graham Thomas’ or the peach pink ‘Abraham Darby’, arching low over the perennials. The roses are pegged and carefully pruned each year to keep an open framework, like a toss of blossoming lace. Garden roses fit perfectly into the role of the fire safe garden: they have low fuel volume and can be pruned open each year to reduce the number of woody stems. Maintenance is the second requirement of the fire-safe garden: if the amount of dead wood on a plant can be reduced, it is that much less likely to burn, if at all.
Nearby, tall-stemmed golden alstroemeria is easy to establish in rich soil, along with a skein of Verbena bonariensis growing like a lacy, five-foot tall screen topped with vibrant purple blooms. Other fine choices include flowering perennials such as Arctotis, Achillea, Gaillardia, Aster, Hemerocallis, and Heuchera. The wide flag-stone path continues around the house to provide varied viewpoints of the floral tapestry, as well as safe access for emergency personnel.
Near the kitchen door is the logical spot for beds of cutting flowers and vegetables mixed with fragrant herbs. I particularly like clusters of oregano, parsley, and tarragon; an edging of golden lemon thyme (Thymus ×citriodorus ‘Aureus’) might surround another small patio. The broad leaves of zucchini contrast perfectly with purple basil and a carpet of edible strawberries in raised beds made from recycled concrete (instead of treated timbers). A cluster of terra cotta pots could accommodate dwarf Southern high bush blueberries (Vaccinium corymbosum), and a half wine barrel might hold yellow fingerling potatoes. Draped with a juicy green seedless grape, a wire trellis can be strung between modern rust-toned poles to define this space, without creating a fuse of flammable material connected to the house. Espaliered apples or dwarf citrus are well suited to serve as a privacy screen and provide fruit for the table and flowers for beneficial pollinators.
Beyond the Garden Zone
Farther from the patio is the Transition Zone where harmony can be found in a combination of low groups of Spanish lavender (Lavandula stoechas), sparkling white Shasta daisy (Chrysanthemum maximum), and lilac flowered mounds of the native Verbena lilacina, all mingling with the fragrant foliage of the non-invasive bronze fennel (Foeniculum vulgare ‘Purpureum’). For the kids and dogs, a circular lawn of waterconserving native carex (Carex praegracilis) can be used to mimic the rich green of a typical suburban lawn—but without the chemicals, water, and labor.
For a little dappled shade, I suggest a few specimens of Western redbud (Cercis occidentalis) placed at the lawn’s edge. Its small form and light texture add height to the landscape without flammable bulk. This tree-for-all-seasons displays masses of magenta flowers along each delicate twig in spring, followed by blue green leaves that color richly with the first cold night of autumn. Later, the winter sunlight emphasizes the tracery of stems and their dark bark.
For areas farther from the house, a shrewd choice would be a blend of low natives that birds, butterflies, and people enjoy alike. Zauschneria or California fuchsia (Epilobium canum) contributes thousands of red trumpet-like flowers above soft billows of gray foliage, from August to November. In this ideal fire-safe garden, deep blue flowers in spring decorate a dark green foliage mat of Ceanothus maritimus ‘Point Sierra’ tumbling between boulders. Pink evening primrose (Oenothera speciosa) spreads a wave of silky blossoms washing around clumps of blue and white Pacific Coast iris. Large shrubs spaced well apart might include distinctive natives such Arctostaphylos pajaroensis ‘Warren Roberts’ or South Africa’s nodding pincushion (Leucospermum cordifolium ‘Veldfire’).
It is wise to dissect the beds farthest from the house with more low stone walls. The walls help to reduce the spread of flames and blowing sparks. They can be accented with masses of succulents. Succulents can be recommended for several reasons, but there are caveats. Many popular types, such as Aloe and Aeonium, are only hardy near the coast, so would not serve well in frostprone inland gardens. Others, like Agave and Yucca have wicked spines and toothed leaf margins that can be dangerous to firefighters trying to move through the landscape, especially in the dark of night.
Maintenance for Fire Protection
No garden, no matter how carefully planted, can be fire safe without proper maintenance. During summer dry seasons, or when there is an unseasonal absence of normal rain, it is best to irrigate the garden sufficiently to keep plants from becoming crisp. Though most of the plants discussed above can withstand drought during extreme conditions, fire resistance is best when the garden is monitored and watered efficiently.
Cleaning away old foliage, removing dead wood, and replacing older plants with new, actively growing ones is the key to resisting flames. Just as a roof needs to be swept free of fallen leaves, the garden needs to be swept clean of old growth. Within the Garden Zone, each plant benefits from a yearly pruning to renew its form, thus removing any dead material that may have accumulated. This reduces fuel volume, and keeps taller shrubs and trees clear of the structures.
The wise gardener also eliminates flammable fences and structures that can create fuses linking the house to the fire, thereby providing clear, easy access for firefighters during the stressful period when they must arrive and quickly evaluate their ability to defend the home. A rigorously maintained garden, appropriately irrigated according to zone, can stop flames before they ever reach the walls of the house.
The fire-safe cottage garden can have a colorful, orderly, and welcoming feel that encourages you to wander and experience each cluster of blossoms while keeping safe your home, your family, and the brave men and women who serve your community.