How-To

Firescaping: Plants That Help Protect Your Property From Fire

By Douglas Kent

Sedum spurium 'John Creech' — *Sedum spurium* 'John Creech'

Whether or not a plant will catch on fire, keep a fire going, and then propel a fire is determined by its physical characteristics. Less flammable plants, those considered fire retardant or fire resistant, share certain physical characteristics. Getting to know these characteristics is fundamentally more important than remembering plants lists.

Deciduous plants are less flammable than evergreens.
Broadleaf plants are less flammable than those with needle and blade like leaves.
Moist and easily bent leaves are less flammable than stiff and leather like leaves.
Thick leaves are less flammable than fine or thin leaves.
Plants that produce a low amount of litter are less flammable than those that produce a lot of litter.
Plants with sap that looks more like water are less flammable than plants with thick, gummy or resinous sap.
Plants without fragrance are less flammable than plants with aromatic qualities.
Plants with silver or gray leaves, which have a high mineral and ash content, are less flammable that those without. However, some plants, such as the highly ignitable native fragrant sages, do not follow this rule.
Plant leaves without hair (cilia) are less flammable than those with hair, including the underside of leaves.

A more or less flammable plant is directly related to its amount of stored moisture and fuel. Ice plant and pine represents the two opposite extremes of flammability.

Every recommended plant can catch on fire. The ability of any of these plants to retard or resist a fire depends on their condition. Any plant that is over-aged, water stressed, infested by pests or improperly cared for is more flammable as a consequence. Truly, landscape maintenance is the fulcrum of fire safety and not plant selection.

Legend

d = Deciduous.

D = Deer resistant. The eating habits of deer vary according to the type of landscape, the season and environmental influences. Some of the plants recommended may be eaten by deer, but have a lower likelihood than other plants. Deer dislike plants with strong odors and fine leaves, typically flammable plants.

E = Erosion controlling plant. A plant capable of slowing erosion protects the soil from the effects of water, wind and gravity. An erosion controlling plant may have one or more of the following characteristics; growth that lays on top of the soil, many surface roots, and/or produces a lot of litter

S = Good screen or wind break. A well maintained screen can block wind, unwanted views and even fire. During a fire a planted screen can act as a barrier to flying embers and slow the speed of wind. Importantly, any plant that is repeatedly sheared builds up a twiggy interior and becomes increasingly flammable over time.

spp. = Half or more of the recommended species in a genus possesses the same characteristics. For example, Geranium spp., which is a Zone 1 ground cover, means that all of the true geraniums can used as a ground cover in Zone 1.

W = Water thrifty plant. This is a relative symbol and can mean no summer water, infrequent summer water, or watering only every two weeks in summer, as in the case of many ground covers.

Note: Picking plants that are able to withstand a garden’s climatic extremes is important to the garden’s flammability, especially in zones 2 and 3. Included with this list are brief descriptions of each plant’s particular tolerances.

Firescaping Zones

Plants within the first 30 feet of a structure are the most fire retarding; they might sizzle and wilt during a fire but will never produce a flame. Fire-retardant plants can catch and help extinguish firebrands. Maintenance is essential in the first 30 feet, and these plants require water, resources, and time. See Zone 1 Plants.

Further out from a structure, fire-retarding plants give way to fire-resistant plants. This group requires much less water and care, yet can still maintain a high degree of fire resistance. Many of these plants also quickly resprout after injury, helping to reduce the chances of topsoil loss after a fire. See Zone 2 Plants.

See Fine Gardening’s interview with Douglas Kent for more information on firescaping and recovering from wildfire.

Firescaping Plants Lists

Zone 1: The Garden Zone / Defensible Space

Extending 30 feet from a house, the garden zone is capable of withstanding flying embers and intense heat. Plants selected in this zone have fleshy, moist and broad leaves. Trees are preferably deciduous. This is the only zone that plants can be water, nutrient and labor dependent.

Zone 1

Ground Covers Perennials Shrubs Trees Vines

or see Zone 2 Plants

* These plants are listed as invasive in some areas of the United States. Please check before planting these plants that you are not in an affected area.

GROUND COVERS

Common Name	Botanical Name
Lawn grasses: bent, Bermuda, blue, fescue, rye, St. Augustine	Agrostis, Cynodon, Poa, Festuca, Lolium, Stenotaphrum
Carpet bugle	Ajuga spp.	Will freeze, but with shade and water, can grow anywhere. / D
Alyssum	Alyssum spp.	Not sweet alyssum. Grows throughout Cal. / W
Wild ginger	Asarum caudatum	Can take a freeze, not intense heat. / D
Bell flower	Campanula spp.	Can tolerate a freeze, not intense heat. / D
Dwarf plumbago	Ceratostigma plumbaginoides	Grows throughout Cal, except in deserts. / D, W
Chamomile	Chamaemelum nobile	Tough. Good lawn substitute. Grown throughout Cal. / D, W (somewhat)
Cranesbill	Erodium	Can tolerate frost, not desert conditions. Prefers coast. / D
Creeping, sheep, and tall fescue	Festuca spp.*	Grown throughout Cal. / D, E, W
Clumping gazania	Gazania (clumping)	Dislikes freezes and long, wet winters. / D
Cranesbill	Geranium spp.*	Hardy. Grown throughout Cal. G. incanum prefers mild coast. / D
English ivy, Hahn’s and smaller-leafed varieties	Hedera helix, H. ‘Hahn’s’, H. ‘Needlepoint’*	Grows everywhere but high mountains and high desert. / D, E, W
Blue star creeper	Isotoma fluviatilis	Grown everywhere but in desert. / D
Bird’s foot trefoil	Lotus corniculatus*	Tolerates tough conditions. Goes dormant in extreme winters.
Ivy geranium	Pelargonium peltatum	Can hold a slope on the coast. Good performer in mild climates. / E
Potentilla, spring cinquefoil	Potentilla tabernaemontanii	Needs protection from extremes. / D
Irish moss, Scotch moss	Sagina subulata	Grows everywhere but desert. / D
Mauve clusters	Scaevola*	Prefers mild, coastal climates, avoid extremes. / D, W
Giant inch plant	Tradescantia albiflora	Aggressive in light shade and can survive freezing and any amount of heat. / D
Nasturtium	Tropaeolum spp.	Thrives along coast. Has naturalized in parts. / D
Veronica, speedwell	Veronica spp.	Versatile enough for every garden. / D
Periwinkle	Vinca spp*.	Grown anywhere but high elevations. V. minor needs more shade in hot, dry summers. / D
Viola	Viola odorata	Prefers the mild coast. Will naturalize in wet winters. / D
Zoysia	Zoysia spp.	Lawn substitute. Likes a sunny summer, not freezes and long winters. / D

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PERENNIALS

Bear’s breech

Acanthus mollis

Durable plant. Grows everywhere but in snow. / D, W

Lily of the Nile	Agapanthus spp.	Durable everywhere but in the high desert and high mountains. / D (somewhat), W
Sea pink, thrift	Armeria spp.	Grows throughout Cal. Performs best by coast. / D
Angel’s hair	Artemisia schmidtiana	Grown throughout Cal. / D, W
Bergenia	Bergenia spp.	Tolerates everything but desert’s heat. / D, W
Canna	Canna	A tropical best at or near the coast. / D
Dusty miller	Centaurea cineraria, C. gymnocarpa, Chrysanthimum ptarmic, Lychnis coronaria, Senecio cineraria	Varies according to variety. Consult local nursery. / D, W
White marguerite	Chrysanthemum frutescens	Thrives anywhere along coast. Dislikes extremes. / D
Shasta daisy	Chrysanthemum maximum	A reliable performer, almost everywhere. / D
Coreopsis	Coreopsis spp.	Excellent color for central and southern coast. / W (a few varieties)
Foxglove	Digitalis spp.*	As an annual, it grows throughout Cal. In woodland areas along central and northern coast, it can naturalize. / D
Wall flower	Erysimum linifolium	Requirements vary with species. / D, W
Euryops	Euryops spp.	Prefers coastal influence. Dislikes deserts with a prolonged freeze. / D, S, W
Ferns	Ferns	From natives to introduced ferns, hundreds of varieties. / D
Day lilies	Hererocallis spp.	Easy plant to grow anywhere. Tuberous and pest free. / D, W
Coral bells	Heuchera sanguinea	Grown throughout Cal. /D
Hosta	Hosta spp.	Better in climates with pronounced winters. Used for foliage. / D
Impatiens	Impatiens spp.	Likes mild coastal climates. / D
Toadflax	Linaria purpurea	Easy to grow anywhere. / W
Lily turf	Liriope and Ophiopogon spp.	Prefers environments influenced by coast. / D
Mallow	Malva spp.*	Grown throughout Cal. Short lived.
Geranium	Pelargonium spp.	Performs best by beach. Tough to grow in extremes. Dependable color.
Garden penstemon	Penstemon gloxiniodes, P. newberryi, P. pinifolius	Widely used in Cal. Annual in cold winter areas / D, W
Philodendron	Philodendron spp.	A hardy tropical. Prefers southern coast. / S
New Zealand flax	Phormium spp.	Can take extremes in heat, not cold. / D, S, W
Lambs’ ears	Stachys byzantina	The shorter the winter, the better. / D
Bird of paradise	Strelitzia spp.	A tropical that dislikes cold. Thrives along southern coast. / D (sometimes), W
Calla	Zantedeschia spp.*	Grown everywhere but desert and high elevations. Will naturalize in wet winter climates. / D

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SHRUBS

Yesterday, today, and tomorrow	Brunfelsia pauciflora calycina	Prefers coast, requires shade inland.
Camellia	Camellia spp.	Likes humidity and dislikes extremes. C. sasanqua can tolerate more heat and sun. / D, S
Mirror plant	Coprosma spp.	Tough in mild winters. / D, E, S, W
Escollenia	Escollenia spp.	Prefers coastal influence. Dislikes extremes. E. illinita has resinous fragrance and should be avoided. / S, W
Gardenia	Gardenia jasminoides	Prefers drier seasons, no frost.
Tropical hibiscus	Hibiscus rosa-sinensis	Prefers coastal humidity. / S
Privet	Ligustrum spp.*	With water it can grow in anything but snow. / S
Mock Orange	Philadelphus spp.	Only P. mexicans likes southern coast. The rest prefer a freeze. / S
Photinia	Photinia fraseri	Grows everywhere but areas with hard freezes, snow. / S, W
Pittosporum	Pittosporum crassifolium, P. tobira, P.tobira* ‘Wheeler’s Dwarf’	Prefers areas with coastal influence, fussy in extremes. / E, S, W
India hawthorn	Rhaphiolepis spp.	Can tolerate mild freezes, likes sun. Hard to grow in high desert and in long, wet winters. / S, W
Rhododendron / Azalea	Rhododendron / Azalea spp.	Fantastic range, found throughout Cal. / D (not azaleas), S
Rose	Rosa spp.	Grown throughtout Cal. / S (some)
Lilac Brush cherry	Syringa spp.* Syzyguim paniculatum	Performs best in areas with a pronounced winter. Risky along central and southern Coasts. / D, S, W (somewhat) Grown in any frost free landscape. Small tree if not pruned. / S
Yellow oleander	Thevetia peruviana	Will thrive in any amount of heat and sun, but a frost will hurt it. / D, S, W
Evergreen huckleberry	Vaccinium ovatum	Native to north and central coast. Likes a mild climate, dislikes extremes.
Chinese snowball	Viburnum macrocephalum	Good everywhere but deserts. / S, W (somewhat)
Japanese snowball	Viburnum plicatum*	See above
Xylosma	Xylosma	Good everywhere but high elevations. / E, S, W

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TREES

Fruit trees	Apple, apricot, cherry, lemon, lime, nectarine, orange, pear, persimmon, plum, prune, tangerine
Maple	Acer spp.*	d – Prefers north, central coasts and desert. Southern Cal stunts growth of all except A. palmatum. / D, somewhat W
Birch	Betula spp.	d – Somewhat tolerant of freeze, not the desert’s heat.
Redbud	Cercis spp.	d – Everywhere but highest elevations. / D
Dogwood	Cornus spp.	d – Grown throughout Cal.
Dragon tree	Dracaena draco	Likes sunny and mild central and southern coast.
Pineapple guava	Feijoa sellowiana	Tolerates any amount of heat, dislikes freezes and soupy coastal conditions. / S, W
Ficus	Ficus spp*.	Grown through Cal. / D (some), S, W (some)
Ash	Fraxinus spp.	d – There is a variety that will grow in your garden. / D, W
Griselinia	Griselinia spp.	Hard to grow in freezes and deserts. / S
Crape myrtle	Lagerstroemia indica*	d – Needs definite seasons. The hotter the summer, the better. A prolonged freeze will kill it. / D, W
Sweet gum	Liquidambar spp.	d – Likes all but desert heat. The more pronounced the seasons, the better fall color. / D
Magnolia	Magnolia spp.	Prefers mild, coastal climates. / D, S
Crabapple	Malus spp.	d – Can tolerate a lot of heat, needs a chilly winter to perform.
Mayten tree	Maytenus boaria	Needs distinct seasons, but dislikes the extremes of either. / D, S, W (somewhat)
Michelia	Michelia spp.	Prefers southern coast. Does well in fog.
Palms	Palms	Only if kept clean are they less flammable. Although an enormous family, palms generally dislike a freeze. / D, S (some), W (some)
Pittosporum	Pittosporum eugenioides, P. rhombifolium, P. undulatum	Prefers coastal climate. Fussy in extremes. / S (excellent), W
Podocarpus	Podocarpus spp.	Prefers coastal climate. / D, S
Ornamental pear	Pyrus spp*.	d (some) – Deciduous varieties grow everywhere but in desert. Evergreen varieties dislike a freeze, prefers coast. / W
California pepper tree	Schinus molle*	Versatile, but dislikes extremes of deserts and mountains. / D, W
Brazilian pepper tree	Schinus terebinthifolius*	Not as hardy to extremes as S. molle. Prefers coast. / D
Giant bird of paradise	Strelitzia nicolai	Grown along coast, and low deserts. Can not take a frost. / D, S, W
Tupidanthus	Tupidanthus calyptratus	A tropical that likes sunny central and southern coasts. / S

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VINES

Trumpet vine	Campsis spp.	d – Hardy vine in cold winter, needs a chill. Aggressive. / D, W
Clematis	Clematis spp.	d – Best performance and selection along the Northern Coast. / D, W
Trumpet vine	Distictis spp.	Although it will tolerate lows to 24 degrees, it does better along coast.
Grape	Grape	d – Grows well in both heat and freeze. Seek local references for best variety.
Creeping fig	Ficus pumila	Lows below 28 degrees will cause die-back. Can take any amount of heat. Durable. / D, W
Guinea gold vine	Hibbertia scandens	Best along Southern Coast. Dislikes even a light frost. But grown along entire coast with some success. / D, W
Jasmine	Jasminum spp.*	d (some) – Grown everywhere but in extremes. / D
Bower vine	Pandorea jasminoides	Prefers the Southern Coast. No wind. / D
Boston ivy	Parthenocissus tricuspidata*	Its evergreen in mild winters. Likes shade in desert.
Pink trumpet vine	Podranea ricasoliana	Thrives in heat, but will drop leaves in frost. / W
Shrub rose	Rosa (polyanthas)	d – Grown successfully throughout Cal.
Star jasmine	Trachelospermum jasminoides*	Prolonged freezes will kill it. Grows everywhere else.
Wisteria	Wisteria spp.*	d – Grown everywhere. Regular pruning will help flower production and appearance. / D, W

*These plants are listed as invasive in some areas of the United States. Please check before planting these plants that you are not in an affected area.

Zone 2: The Greenbelt / Fuel Break

Extending 31 feet from a structure to 70 feet, and much further on slopes, this zone will stop a ground fire. Plants recommended in zone 2 are considered the most fire retardant because they maintain low fuels and high moisture despite droughts, freezes, infestations and possible neglect. Trees and shrubs are kept isolated and only used to serve a variety of functions, such as privacy, heat and cold reduction and wildlife enhancement. Ground covers grow no higher than 18 inches. Picking plants that are compatible with the naturally occurring conditions is critical to the success of this zone.

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Zone 2

Ground Covers Perennials Shrubs Trees Vines