Fire-resilient Landscapes: Creating Beautiful Gardens for Defensible Space

November 4, 2021

Association of Professional Landscape Designers, California Chapter

Mike Evans, Tree of Life Nursery

CRITERIA FOR LANDSCAPE DESIGN

Aesthetic

Engagement (human)

Appearance

Wildlife – urban habitat

Biodiversity

Target species

Beneficial invertebrates (including pollinators)

Locally relevant

Practical

Water conservation

Sensible maintenance needs

Sustainable, regenerative

Cost effective

Pragmatic

Watershed, erosion

Availability of materials

Fire safety

NATURALISTIC DESIGN

Meets criteria listed above

NATIVE PLANTS

Components of naturalistic design

Turgidity – water content in leaves and stems

FIRE SAFETY

Important, but when put as top priority in Criteria, limits everything else

Evaluate each site and prioritize accordingly

Landscape design for fire safety cannot completely mitigate previous mistakes

Regional planning blunders

Site design errors

Location, access

Architecture, building materials

Intended use of site

BASIC CONSIDERATIONS

Likelihood of fire

Source of ignition

Conditions under which fire would be a serious threat

Potential severity of fire

Most vulnerable places or site factors

BASIC PRINCIPLES – PLANTS

Avoid using plants with high content volatile oil 

Many conifer species

Laurel sumac (Malosma laurina)

Chamise (Adenostoma fasciculatum)

Avoid using perennials and annuals that can become “flash fuels” on the ground

Deerweed (Lotus scoparius)

Tall, tangles annuals from seed i.e.: tall lupines and phacelia

Cool season grasses which are summer dry/dormant

Avoid using subshrubs that can build up dead wood in their centers

California buckwheat (Eriogonum fasciculatum) – tall growing forms

Sages (Salvia species) – tall growing forms

Coastal sagebrush – (Artemisia californica) – tall growing forms

Avoid creating fuel ladders

Low, medium, and tall plants – don’t plant close to each other

Avoid overcrowding

Proper spacing

Planned succession

Plan for pruning maintenance, short and long term

Keep low plants low, promoting lots of new growth 

Keep medium and tall plants thinned, removing inner branches

Keep dead wood out of all plants

Keep invasive exotics out

BASIC PRINCIPLES – DESIGN

Consider all the criteria

Place fire safety in in proper place in the order of considerations

PLANTS – LOW

Grindelia stricta

Baccharis pilularis (groundcover varieties)

Iva hayesiana

Ceanothus (groundcover varieties)

Arctostaphylos (groundcover varieties)

Ribes viburnifolium (shade)

Salvia (low cultivars)

Eriogonum (low cultivars)

Adenostoma (low cultivars, i.e.; ‘Nicolas’)

PLANTS – MEDIUM

Rhamnus californica (low varieties)

Rhus integrifolia, R. ovata

Ceanothus species and cultivars (medium height)

Arctostaphylos species and cultivars (medium height)

Cercocarpus betuloides

PLANTS – TALL

Quercus species

Prosopis species

Prunus lyonii

Lyonothamnus floribundus ssp. asplenifolius

PLANTS – SPECIMEN

Nolina species

Yucca species

Agave species

PLANTS – FIRE RETARDANT AND FIRE RESPONDENT

Isocoma menziesii

Ericameria species

Atriplex species

Berberis nevinii

Simmondsia chinensis

Shepherdia argentea

Prunus ilicifolia

Sphaeralcea ambigua

Viguiera laciniata

Calliandra californica

Sphaeralcea ambigua

Cleome arborea

Rhamnus californica

PLANTS – SHADE

Ribes viburnifolium

Symphoricarpos mollis

Iris ‘Pacific Coast Hybrids’

Heuchera maxima plus cultivars

Solidago californica

Monardella species

Fragaria californica

Potentilla californica

Rhamnus californica

Philadelphus californica

Arctostaphylos (groundcover varieties)

Ribes species (currants and gooseberries)

PLANTING COMBINATIONS

Opuntia littoralis patches, or rock outcrops interplanted with:

Romneya ‘White Cloud’

Rosa californica

Sambucus mexicana

Epilobium californicum (many cultivars available)

Eriogonum species

Gambelia speciosa

Verbena lilacina

Mirabilis californica

Mimulus aurantiacus, M. puniceus

Other showy low growing flowering natives

Plus: All of the following, interplanted with Iva)

Iva hayesiana – nondescript dull green groundcover interplanted with:

All of the above (interplanted with Opuntia) plus:

Mimulus aurantiacus, M. puniceus

Penstemon spectabilis

Venegasia carpesioides

Viguiera laciniata

Hesperoyucca whipplei

Heteromeles arbutifolia

Other showy low growing flowering natives

BARE EARTH, AGGREGATE TOPDRESS

Strategic placement

Aesthetic design

Bisected by plantings

Effective wildlife habitat 

Pollinators, especially native bees

Ecological “Edge Effect”

Planted with xeric species

Agave species

Opuntia species

Yucca schidigera

Salvia species and cultivars

Eriogonum species

Condea (Hyptis) emoryi

Fallugia paradoxa

Trichostema lanatum

Arctostaphylos species and cultivars

tall, thineed, artfully pruned

California native plants

Resilient to human efforts to reduce fire ”risk”

(to a point)

Resilient to fire

Naturalistic design employing nature’s examples

Biodiversity

Beauty in truly sustainable landscapes

FIRE SAFE, FIRE CONSIDERATE, FIRE RESILIENT 

Develop a design philosophy taking examples from nature’s beauty and biodiversity to make functionally sustainable gardens that are fire-safe (well, more like fire considerate).

Use only native plants in fire-safe landscapes because the pressures of land development and vegetation control statewide in the name of “fire prevention” are so great.simply stated we have to:

“Do enough before it’s too late.”

Richard Stephen Felger (1926-2020)

NATURE IS ALWAYS THE MODEL