The following list
of plants contains those found in the references that were recommended
for use in fire prone environments by at least 3 references. All of the
plants listed here were given either a high or moderate fire resistance rating
in the references where a rating was assigned, or found listed in the references
that categorized plants as fire resistant without assigning a degree of resistance.
In most cases, the terms used in the ranking were not defined, and if they
were, there is no agreed upon standard definition. For this reason, the plants
are listed in this chapter without any attempt to rank them.
The list is sorted
by plant form -- groundcovers, shrubs, trees, etc. Some species may appear
twice (e.g. once as a groundcover and then again as a shrub) because they
have properties attributed to both forms
It is important
to note that a plant's fire performance can be seriously compromised if not
maintained. Plants that are not properly irrigated or pruned, or that are
planted in climate areas not generally recommended for the plant, will have
increased fire risk and will likely make the mature plant undesirable for
landscaping in high fire hazard zones.
(Please click on video right arrow to play video)
Table
1. Plants with a favorable
fire performance rating in 3 or more references. Some plants may have invasive (indicated as ), or other negative characteristics
that should be considered before being selected for use in parts of
California. For more information please go to http://www.caleppc.org/ .
The following list
of plants contains those found in the references that are definitely not recommended for use in fire prone environments by at least 3 references. All of the plants listed here were given either a low fire resistance rating
in the references where a rating was assigned, or found listed in the references
that categorized plants as being fire prone, without assigning any relative
degree of resistance.
The list is sorted
by plant form -- groundcovers, shrubs, trees, etc. Some species may appear
twice (e.g. once as a groundcover and then again as a shrub). For a complete
description of the plant, including its mature characteristics, climate zones,
and information on erosion control, drought tolerance and cold tolerance,
please refer to the landscape vegetation database.
Characteristics of plants not recommended for fire prone areas.
The plants in this
group have some commonly shared characteristics. Most of these plants are
characterized by:
a high surface
area to volume ratio.
a low moisture
content.
a high percentage
of dead matter or debris.
Plants that possess
all of these characteristics are likely to have an unfavorable fire performance
rating. Comparison of the general characteristics of a plant not included
in this list with those listed above could result in a decent estimate of
the plant's fire performance.
It is possible
that a plant listed as fire resistant, but allowed to grow unchecked and poorly
maintained could possess the characteristics listed above and therefore be
a liability. Proper maintenance of landscaping is crucial and cannot be overlooked. Conversely, it is also possible that a plant with an unfavorable rating
could perform well with special irrigation and maintenance regimes. However
this approach is not advisable since long term irrigation and maintenance
cannot be guaranteed.
Table 2. Plants with
an unfavorable fire performance rating in 3 or more references.
Scientific Name
Common Name
Plant Type
Plant Form
Reference #
Abies spp.
Fir
evergreen
tree
4,8,40,41
Adenostoma
fasciculatum
Greasewood chamise
evergreen
shrub
3,4,8,9,30,40,41,42
Adenostoma
sparsifolium
Red shanks
evergreen
shrub
8,9,30,42
Coprosma pumila
Prostrate coprosma
evergreen
groundcover
9,25,53
Cortaderia
selloana
Pampas grass
evergreen
grass
4,8,9,40
Eriogonum
fasciculatum
California buckwheat
perennial
shrub
4,40,41,42
Eucalyptus
globulus
Eucalyptus globulus,
Blue gum
evergreen
tree
4,9,8
Larix spp.
Larch
deciduous
tree
8,40,41
Lonicera japonica
Japanese honeysuckle
evergreen
vine
8,40,41
Palms
Palm
evergreen
tree
8,40,41
Picea spp.
Spruce
evergreen
tree
4,8,40,41
Pickeringia
montana
Chaparral pea
evergreen
shrub
8,40,41
Pseudotsuga
menziesii
Douglas-fir
evergreen
tree
4,40,41
Spartium junceum
Spanish broom
evergreen
shrub
4,40,41
Taxus spp.
Yew
evergreen
tree
4,40,41
Thuja spp.
Arborvitae
evergreen
tree
4,8,40,41
Tsuga spp.
Hemlock
evergreen
tree
8,40,41
List of References for Plant Fire Performance
Ratings:
Ref #
Author
Title
Year
Publisher
Reference Summary
1
California Department of Forestry
Fire Safe: Inside and Out
Date Unk.
California Department of Forestry Publication
Defines fire retardant plants as those easily maintained and
pruned, drought tolerant in some cases, can be grown without accumulating
dead branches, needles or leaves, have a low sap or resin content,
and grow close to the ground.
2
Gaidula, Peter
Wildland Fuel Management Guidelines for the CA State Park System
1976
California Department of Parks and Recreation
This reference does not offer a definition of fire retardance
with respect to plants, however it offers suggestions of certain plant
characteristics to keep in mind when clearing brush to reduce fire
hazard: plant vigor, poisonous plants, effects of plants on soils,
value for wildlife food and cover, aesthetic values, and relative
flammability.
3
Tarbes, J.A.
Physical Characteristics of Chamise in Relation to Flammability
and Combustibility
1980
San Francisco State University, CA
Defines fire performance characteristics of chamise species
only.
4
Sunset
Big Job #1: Landscape to Fight the Fire
1992
Lane Magazine and Book Company, June
Defines highly flammable plants as those that are accumulators
of fuel, not maintained or pruned periodically, and contain high oil,
high resin or low moisture in leaves and branches.
5
Sunset
Brush Clearing for Fire Safety
1968
Lane Magazine and Book Company, October
Describes fire retardant plants as those that are low-growing
shrubs, non-native brush, and well maintained and watered brush.
6
California State Fire Marshal Journal
Landscape for Home Fire Safety
1989
CSFM Journal, No. 2, March/April
Defines flammable vegetation as plants containing volatile
resins, oils, gums and terpenes, and plants that have accumulations
of dead twigs and branches on mature live plants. This reference also
defines fire retardant plants as those with a high moisture content,
high in ash, well irrigated, free of dead matter, and low volume shrubs.
7
City of Los Angeles, Department of Arboreta & Botanic Gardens
Green Belts for Brush Fire Protection and Soil Erosion Control
in Hillside Residential Areas
Date Unk.
City of Los Angeles, Dept. of Arboreta & Botanic Gardens,
Arcadia, CA
The term fire retardant is used to describe plants inherently
less flammable than others. Rates plants as HIGH(greatest fire retardance)
low-growing succulent plants with thick, fleshy leaves and/or stems.
MODERATE(moderate fire retardance) low-growing herbaceous perennials
and sub-shrubs not distinctly succulent. LOW(low fire retardance)
low-growing shrubs and sub-shrubs with rather dry, leathery or rigid
leaves and branches.
8
East Bay Municipal Utility District Water Conservation Division
Firescape: Landscaping to Reduce Fire Hazard
1995
Community Services Department and EBMUD Board of Directors
Defines flammable or hazardous vegetation as any vegetation,
including ornamental, that either by it's intrinsic characteristics,
placement, or lack of care is easy to ignite, spreads fire rapidly,
produces high heat, or creates fires that are difficult to suppress.
Defines a fire resistant plant as less likely to burn, grows close
to the ground and takes longer to ignite.
9
Brende and Shapiro Tree And Shrub Care
List of More and Less Fire Prone Plants
Date Unk.
Brende and Shapiro Tree and Shrub Care, Berkeley, CA
This reference suggests that any plant can be fire-prone if
not properly maintained. Arrangement, spacing, density and dryness
of the vegetation is probably more crucial than what species are planted.
10
Gilmer, Maureen
California Wildfire Landscaping
1994
Taylor Publishing Company, Dallas, TX
Plants are grouped as the most fire retardant if they retain
high levels of moisture in their leaves and stems; these plants are
mostly succulents and have low-growth habits. Moderate fire retardance
is given to plants that are non-succulent with leaves that retain
a high moisture content. Plants with low fire retardance are those
with leathery and dry leaves.
11
California Department of Forestry and Fire Protection
Fire-Safe Demonstration Garden
Date Unk.
Santa Clara Ranger Unit
A list of plants is offered without definition of fire retardance.
12
Berkeley Horticulture Nursery
Fire Resistant Plants
1991
Berkeley Horticulture Nursery, Berkeley, CA
Defines fire resistant as being able to withstand high temperatures
for prolonged periods without igniting and does not readily support
open flames.
13
Maire, Richard G.
Landscape to Prevent Fire
1962
University of California Agricultural Extension Service
Fire retardance is not defined in this publication.
14
Northeast Ridge, Southwest Diversified
Final Habitat Fire Buffer Program
1990
Northeast Ridge, Brisbane, CA, Southwest Diversified, INC.
This reference states that all plants will burn under the worst
conditions, but some are more suitable for fire-prone areas because
of one or more of the following characteristics: high mineral content,
high moisture content, low volume of fuel.
15
D'Alcamo, Susan; Rice, Carol L.
Appropriate Landscaping Plants to Reduce Fire Hazard
Date Unk.
East Bay Chapter, California Native Plant Society, Berkeley,
CA
Supplies a list of California native plants to be used to establish
a more fire retardant environment because of one or more of the following
characteristics: high mineral content, low fuel volume, high moisture
content.
16
Red Shingle & Handsplit Shake Bureau
The Green Fireman Plan
1988
Red Cedar Shingle & Handsplit Shake Bureau, Bellevue, WA
This references bases its recommendations of fire retardance
on the following: plants with a high moisture content, low volume
shrubs, and (up to a point) plants with a high ash content.
17
Phoenix Team of the Environmental Action Committee of West
Marin
After the Vision Fire
1996
Phoenix Team of the Environmental Action Committee of West
Marin
This reference provides a list of suggested fire retardant
plants; fire retardant is not defined.
18
Morris, Wendy; Barbar, J.R.
Design and Siting Guidelines: Bush Fire Protection for Rural
Houses
Date Unk.
Country Fire Authority, Victoria
This reference suggests that the degree of fire retardance
of a tree or shrub depends on the amount of moisture in the leaves,
the amount of oil or resin in the leaves, and/or the amount of dead
matter that remains on the tree. Trees and shrubs were rated as follows:
HIGH - most suitable; MODERATE - suitable. Groundcovers were rated
as follows: HIGH - very succulent, MODERATE - semi-succulent.
19
Brush Fire Safety Committee
Make it Safe to Live in the Hills: Fire Resistant Plants
Date Unk.
Brush Fire Safety Committte, Los Angeles, CA
This reference explains that some plants are relatively non-flammable
because they are able to withstand high temperatures for prolonged
periods without igniting and do not readily support open flames.
20
Radtke, Klaus W.H.
A Homeowner's Guide to Fire and Watershed Management at the
Chaparral/Urban Interface
1993
County of Los Angeles, CA
Fire retardance was rated as follows: HIGH - very highly fire
retardant. MODERATE - medium fire retardance. LOW - low very retardance.
21
Radtke, Klaus W.H.
Living More Safely in the Chaparral/Urban Interface
Date Unk.
U.S. Dept. of Agriculture, Pacific Southwest Forest and Range
Experimant Station, Gen.Technical Report PSW-67
Fire retardance was rated as follows: HIGH - very highly fire
retardant. MODERATE - medium fire retardance. LOW - low very retardance.
22
Maire, Richard G.; Goodin, J.R.
Landscape for Fire Protection
1969
University of California Agricultural Extension Service
Refers to Los Angeles Arboretum research. Makes clear the point
that the term "fire resistant" is used, but that there is not a plant
that exists that will not burn given the right conditions. Also suggests
that well-maintained and well-watered plants will not burn as readily
as those left dry and unmaintained.
23
Grounds Maintenance
Flirting With Fire
1988
Grounds Maintenance, August 23(8):32,36,38,104.
Erosion control was rated as : LOW - 30% or less. MODERATE
- 60%. HIGH - 60% or steeper.
24
County of Los Angeles Arboreta & Botanical Gardens
Fire Retardant Plants for Hillside Areas
1970
County of Los Angeles Arboreta and Botanical Gardens, Los Angeles,
CA
Bases fire retardance on relatively high moisture content and
prostrate or creeping growth characteristics. Rated as follows: HIGH
- succulents (90-95% moisture content). MODERATE - non-succulents(80-95%
MC) or 70-80% MC. LOW - 60-75% MC.
25
Santa Barbara City Fire Department
Firescape Demonstration Garden
Date Unknown
Santa Barbara City Fire Department, Santa Barbara, CA.
This reference offers only a list of suggested fire retardant
plants, no criteria are given.
26
Coate, Barrie
Water-Conserving Plants and Landscapes for the Bay Area
1990
East Bay Municipal Utility District
Only offers a list of plants considered to be more fire retardant
than most plants. No criteria offered.
27
Rice, Carol
Effects of Drought on Landscaping in the Paint Fire
1991
Wildland Resource Management, Walnut Creek, CA
Lists species with the highest moisture content and therefore
probably the most fire retardant. Also lists the driest plants --
these were classified as not being recommended for fire prone areas.
28
City of San Carlos
Fire Resistive Plants
1996
The City of San Carlos, CA
Gives a list of herbaceous perennials, succulents, trees and
groundcovers considered to be fire retardant. No definition offered.
29
Beatty, Russell
Designing Gardens for Fire Safety
1991
Department of Landscape Architecture, University of California,
Berkeley
Rates plants fire retardance based on the following: Broad-leafed
plants tend to be more fire retardant than those with needle-like
or very fine leaves; dense compact forms and low prostrate plants
are more effective at retarding fire than more open or upright plants.
30
Harlass, Sherry
How to Firescape to Reduce the Fire Hazard
1993
Nursery Manager, December
Defines a fire retardant plant as one that burns slowly.
31
Orinda Fire Protection District
Protect Your Home: Landsape For Fire Protection
Date Unk.
Orinda Fire Protection District
Offers a few fire retardant landscape plants with no criteria
for classifying them as such.
32
California Department of Forestry
Fire Safe, California!
Date Unk.
California Department of Forestry and Fire Protection, Sacramento,
CA
Classifies fire retardant plants as those that are hardy succulents
and flat ground covering plants that are kept groomed and free of
dry leaves.
33
City of Santa Barbara Fire Department
City of Santa Barbara Firescapes Demonstration Garden
Date Unk.
City of Santa Barbara Fire Department, Santa Barbara, CA
Defines fire resistant plants as those plants that can regenerate
growth, despite burning and fire retardant plants as those which are
less flammable than others.
34
Bowker, Mike
High Danger this Year: Preventing the Firestorm
1995
Motorland/CSAA, July/August
Considers that fire retardant plants share the following characteristics:
grow close to the ground, have a low sap or resin content, grow without
accumulating dead matter, are easily maintained and pruned, and are
often drought tolerant.
35
South County Fire
Protecting Your Home From a Brush Fire
Date Unk.
South County Fire
Offers only a list of plants, without explanation or definition.
36
Sunset
Protecting Your Home Against Brushfire
1983
Lane Publishing Company
Lists succulents as having the greatest fire retardance. Herbaceous
perennials if well-watered and woody groundcovers if well-watered
are also highly recommended.
37
Department of Water Resources, The Resources Agency
Plants for California Landscapes: A Catalog of Drought Tolerant
Plants
1979
State of California, The Resources Agency, Department of Water
Resources, Bulletin 209, September
Offers a list of recommended plants without explanation or
definition.
38
LeMay, David B; Wayne G. Mitchell
Recommended Low-Fuel Volume Species for San Luis Obispo County
1978
San Luis Obispo, CA: Central Coast Fire Prevention Association
Rates species of plants as either having HIGH/MODERATE or LOW
fire retardance; no explanation or definition of terms.
39
Martin-Richardson, Brenda; San Luis Obispo County Fire Department
A Homeowner's Guide to Fire Resistant Plants for the San Luis
Obispo Area
Date Unk.
San Luis Obispo, CA: CA Dept. of Forestry & Fire Protection
and The San Luis Obispo County Fire Dept.
Lists fire retardant plants for the San Luis Obispo area; no
criteria offered.
40
Moritz, Ray; Pavel Svihra
Pyrophytic vs. Fire Resistant Plants
1996
University of California Cooperative Extension HortScript February
No. 18
Defines fire resistant as: most broad leaf deciduous trees;
leaves tend to be supple, moist and easily crushed; trees tend to
be clean, not bushy, and have little deadwood; shrubs are low-growing
(<2') with minimal dead material; tall shrubs are clean, not bushy;
sap is water-like and typically does not have a strong odor; and plants
that will not sustain a flame when ignition is attempted.
41
Moritz, Ray
Pyrophytic vs. Fire Resistant Plants
1995
San Rafael Fire Department, FireSafe Marin. May
Defines fire resistant as: most broad leaf deciduous trees;
leaves tend to be supple, moist and easily crushed; trees tend to
be clean, not bushy, and have little deadwood; shrubs are low-growing
(<2') with minimal dead material; tall shrubs are clean, not bushy;
sap is water-like and typically does not have a strong odor; and plants
that will not sustain a flame when ignition is attempted.
42
Perry, Bob
Trees and Shrubs for Dry California Landscapes
1989
Land Design Publishing, Claremont, CA
Fire retardance was rated as follows: LOW - high fire hazard
species and undesirable domestic plant. MODERATE - acceptable domestic
plant that requires ample amounts of water for best performance and
valuable watershed species that should be thinned to reduce foliage
mass, and be retained in limited numbers to prevent high intensity
fires. HIGH - low-growing and high fire retarding plants and low fuel
volume native and introduced species.
43
Ellefson, Connie Lockhart; Thomas L. Stephens; Doug Welsh,
Ph.D.
Xeriscape Gardening
1992
Macmillian Publishing Company, New York
Offers plant lists only with no definition of drought or drought
tolerance.
44
Brenzel, Kathleen Norris (editor)
Sunset Western Garden Book
1995
Menlo Park, CA: Sunset Publishing Corporation, March
This reference was used to gather mature plant characterisitics
and information on drought tolerance, climate zones and erosion control.
Drought tolerance is defined as requiring little or no dry season
water. Climate zones are defined for the western states, each species
is listed with a list of zones that it will tolerate. The zone map
for this publication was generated from Sunset Western Garden Book's
climate zone information. Note is made if a plant is considered to
be useful in erosion control, but further explanation is not offered.
45
U.S. Dept. of Agriculture, Soil Conservation Service, Davis,
CA
Plant Materials Study
1976
U.S Dept. of Agriculture, Soil Conservation Service, Davis,
CA
Offers information on plants suitable for erosion control.
46
Deering, Robert Bowman
A Study of Drought Resistant Ornamental Plants
1955
Davis, CA: University of California, Davis
Offers plant lists only with no definition of drought or drought
tolerance.
47
International Erosion Control Association
Proceedings of International Erosion Control Association, 8th
Conference
1977
Seattle, WA: The Association. Feb 24-25, 1977, Airport Marina
Hotel, Burlingame, CA.
Offers species recommended for erosion control without providing
a rating or a definition.
48
Edmuson, George C.
Plant Materials Study: A Search for Drought-Tolerant Plant
Materials for Erosion Control, Revegetation and Landscaping along
California Highways: Final Report
1976
U.S Dept. of Agriculture, Soil Conservation Service, Davis,
CA
Offers plant lists only with no definition of drought or drought
tolerance.
49
Resource Management International, Inc.
Windbreaks Demonstration Project: Final Report
1988
Sacramento, CA: The Office of Land Conservation, California
Department of Conservation
Offers plant lists only with no definition of drought or drought
tolerance.
50
Lenz, Lee W.; Dourley, John
California Native Trees And Shrubs
1981
Rancho Santa Ana Botanic Garden, Claremont, CA
Offers plant lists only with no definition of drought or drought
tolerance.
51
Nehrling, Arno; Irene Nehrling
Easy Gardening with Drought-Resistant Plants
1975
New York: Dover Publications, Inc.
Defines drought as less than 1" of rainfall/week or </=
20" for growing season. Plants considered drought tolerant will survive
under these conditions.
52
Hazlewood, Walter G.
A Handbook of Trees, Shrubs, and Roses
1968
Sydney, Australia: Angus & Robertson, LTD
Defines drought tolerant plants as those recommended for "hot,
dry areas where they will not get any watering."
53
Orange County Fire Department
Report of the Wildland/Urban Interface Task Force
1994
Developed by the Orange County Wildland/Urban Interface Task
Force Subcommittee on Fuel Modification. July Attachment C
Defines plants that are not suitable for fire prone areas as
possessing some or all of the following characteristics: are known
to be especially combustible; have dry or deciduous foliage during
part of the year; develop deciduous or shaggy bark; develop dry or
dead undergrowth.
54
Perry, Bob
Landscape Plants for Western Regions: An Illustrated Guide
to Plants for Water Conservation
1992
Claremont, CA : Land Design Publishing
Categorizes landscape plants based on the water needs. Also
provides information on the mature characteristics of plants.
55
Hickman, James C. (editor)
The Jepson Manual: Higher Plants of California
1993
University of California Press, Berkeley and Los Angeles, CA
Provides information on plant classification and mature plant
characteristics.
56
The Staff of the Liberty Hyde Bailey Hortorium, Cornell University
Hortus Third: A Concise Dictionary of Plants Cultivated in
the United States and Canada
1976
New York, NY: MacMillan Publishing Company, Inc.
Provides detailed information on mature plant characteristics.
57
Costello, L.R.; K.A. Jones
Water Use Classification of Landscape Species: A Guide to the
Water Needs of Landscape Plants
1994
Half Moon Bay, CA: University of California Cooperative Extension,
San Mateo/San Francisco Counties
Provides recommended watering for over 1200 landscapes plants
based on 6 climate regions of California.