Reducing Wildfire Risk While Achieving OtherLandscaping Goals

by Cotton K. Randall, L. Annie Hermansen-Báez, and Glenn Acomb

Fire in the Wildland-Urban Interface:

Many people move to woodland or other natural areasto be closer to nature and to escape urban stress. Thesehomeowners tend to value landscaping that emphasizesscenic beauty, wildlife viewing, privacy, and shade. Theymay prefer native plants around their homes to enhancewildlife habitat. They may be interested in conserving waterand energy for economic and environmental benefits. Thereare several landscaping programs that help homeownersachieve these goals, such as the Backyard Wildlife Habitat™program that focuses on improving wildlife habitat aroundthe home to enhance wildlife viewing.

Life in the wildland-urban interface (areas where homes orother structures are adjacent to or intermixed with forests or

other rural land uses) provides multiple benefits for thosethat choose to live there. However, along with these benefitscome risks. Risk of wildfire is high in many parts of the Southdue to the region’s fire-prone ecosystems. Many plants thatevolved in these ecosystems actually benefit from periodicfire, and they sometimes have characteristics that supportthe spread of fire, such as highly flammable leaves orbranches. The landscape surrounding a home or other struc-ture can become fuel for a wildfire, contributing greatly to therisk of damage to the structure. Vegetation that is overgrown,continuous, and close to a home may improve wildlife habi-tat or conserve energy, but it also increases the home’s vul-nerability to wildfire. One way to reduce fire risk to homes

What do you value in Your LANDSCAPE?

continued on next page

This is a joint product of the University of Florida, Institute of Food and Agricultural Sciences (IFAS) and the USDA ForestService, Southern Research Station, Southern Center for Wildland-Urban Interface Research and Information.

Wildfire risk reduction Wildlife habitat creation orenhancement

Water conservation Energy conservation

landscaping goals

and other structures is to incorporate principles of fire-wise landscaping, which is part of the national Firewiseprogram. Firewise landscaping incorporates fire safetyinto landscape design. It may not be necessary, howev-er, if you are located within an urban or suburban areaand are completely surrounded by other developments.In that case you can give priority to other landscapegoals. Can a homeowner incorporate firewise landscap-ing without sacrificing other landscaping goals? Thisfact sheet compares several home landscaping goalsand their key principles to firewise landscaping princi-ples to help answer this question.

Comparing FIREWISEto other common landscaping goalsIn this section, we give a brief overview of severaldifferent landscaping goals, including wildfire risk reduc-tion (Firewise), wildlife habitat creation or enhancement,water conservation, and energy conservation. We introducethe main principles and compare each to firewise land-scaping. We also briefly discuss examples of programs andguidelines that incorporate multiple goals. Table 1 listssome of the apparent conflicts between firewise and differ-ent landscaping goals. More detailed information abouteach landscaping goal can be found in the publications orwebsites listed in the reference section at the end of thisfact sheet.

Wildfire risk reduction (Firewise)

A key principle when landscaping to reduce wildfire risk,otherwise known as firewise landscaping, is to create anarea of defensible space that extends at least 30 feet out-ward from the house in all directions. Within this defensi-ble space, vegetation should be modified to break up thecontinuity of plants. The extent to which vegetation is mod-ified is generally determined by distance from the house.Through ongoing maintenance, highly flammable plantsshould be removed or isolated, vertical and horizontal sep-aration (Figure 1) between plants or plant groups should becreated and dead plants and plant materials (e.g. fallenleaves, dead branches) should be removed (Figure 2).These practices help to disrupt the spread of fire throughthe landscape, allowing the home to better survive on its

continued from page 1

own and providing firefighters with sufficient room to oper-ate. The Firewise program (www.firewise.org), sponsoredby the National Wildfire Coordinating Group (NWCG), pro-vides information to help homeowners, fire fighters, andcommunities incorporate firewise landscaping.

figure 2. The landscap-ing around this housewas modified to reducefire risk. The denseshrubs and flammablesaw palmettos (Serenoarepens) that were close tothe house (A; beforephoto) were removed andreplaced with low-grow-ing shrubs and ground-covers that are low inflammability (B; afterphoto). The area ofdefensible space was alsoexpanded. Because thearea shown in these pho-tos is within 30 feet fromthe house, almost all ofthe saw palmettos wereremoved (a highly flam-mable plant). However,in other areas of theproperty outside thedefensible space smallpatches of palmettoswere retained for theirwildlife and aestheticvalue.

2a

2b

Phot

oC

redi

t:La

rry

Kor

hnak

Phot

oC

redi

t:La

rry

Kor

hnak

2Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

figure 1. Vertical separation (V) should be maintained between plants andplant groups by removing all ladder fuels from this area and pruning lowerbranches on trees up to 10 feet from the ground. Horizontal separation (H)should be maintained by separating groups of plants or landscape beds bynonflammable areas (e.g. decorative gravel or stepping stones) and keepingplants at least 2 to 5 feet out from the home.

1

V HH

figure 3. By planting landscape plants that provide food for wildlife, youcan enhance the value of your yard as habitat. The Indian blanket flowers(Gaillardia puchella) in the forefront of this picture attract butterflies, whilebeautyberry (Callicarpa americana) near the house provide berries for birdsand other wildlife.

Wildlife habitat creation or enhancement

When landscaping to create or enhance wildlife habitat,the main objective is to provide the key resources thatwildlife require - food, cover, water, and space. A nationallandscaping program that focuses on creating wildlifehabitat is the Backyard Wildlife Habitat™ Program of theNational Wildlife Federation® (www.nwf.org/backyard-wildlifehabitat). While most wildlife landscaping programsseek to increase overall wildlife diversity in the yard andsurrounding areas, landscaping programs also exist thatare designed to increase populations of specific typesof wildlife (e.g., woodpeckers, butterflies, songbirds).Regardless of which program is used, principal wildlifehabitat practices are to limit the amount of lawn (lawnoffers very little food or cover for wildlife), provide water,plant native plants that provide food and/or cover (Figure3), and remove invasive exotic plants (they may take overnatural habitat). In addition to providing wildlife habitat,native plants can help conserve local plant biodiversity andreduce required maintenance if appropriate species areselected (i.e., “right plant, right place”). The use of nativeplants in fire-prone ecosystems, however, may conflict withfirewise principles, as some natives adapted to suchecosystems are highly flammable. Vertical layering of vege-tation in the landscape (Figure 4) and retention of deadplant materials (standing dead trees and brush piles) nearthe home are recommended because they provide coverand habitat for foraging and nesting. However, these rec-ommendations conflict with firewise landscaping, which

advocates vertical separation and removing flammabledead plant materials from the defensible space.

Phot

oC

redi

t:La

rry

Kor

hnak

3

3Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

Water conservation

The primary goal of landscaping for water conservation,commonly called waterwise landscaping or xeriscaping, isto create landscapes that use only minimal supplementalwater resources once plants are established. The mainprinciple of waterwise landscaping is to select “the rightplant for the right place”, which means choosing plantsthat are well adapted to the specific conditions where theyare to be planted (e.g., soil type, soil moisture, amount ofsunlight, and temperature). Selecting plants in this mannerreduces the demand for supplemental resources, such aswater, fertilizers, and pesticides (Figure 5). Waterwise rec-ommends using lawn sparingly and only in high trafficareas, such as play areas, because lawns have high waterrequirements. Both waterwise and firewise recommendgrouping plants in islands. Waterwise makes this recom-mendation so that plants with similar water requirementsare placed together, while firewise recommends this so asto create fuel breaks (islands should be separated by atleast 10 feet with materials that won’t burn such as wellmaintained lawn or rock). Waterwise landscapes requireless water to stay healthy. This becomes especially impor-tant during drought periods when restrictions on wateringmay be implemented and the risk of wildfire is greater.

figure 4. To the left ofthe house, there isalmost continuous vege-tation from the groundto the tops of the trees.This vertical layeringprovides good wildlifehabitat, but it is not con-sidered firewise.

4

Phot

oC

redi

t:La

rry

Kor

hnak

figure 5. In the front ofthis house, the homeown-ers installed mulch andplanted a variety of nativeand ornamental shrubsthat require little or noirrigation once established(for water conservation).The landscape also hasvertical and horizontalseparation between plants,which provides protectionfrom wildfire.

Phot

oC

redi

t:La

rry

Kor

hnak

Energy conservation

Strategic placement of trees, shrubs, and other landscapeplants around a house can reduce the energy required tokeep homes and surrounding areas comfortable during thesummer and winter months. Reductions in cooling costsare achieved by strategically planting shrubs and trees toprovide shade and funnel wind towards the house duringthe summer. Heating costs can be reduced during the win-ter by arranging rows of shrubs or trees at set distancesfrom a house to block the winter winds (windbreaks)and/or by arranging shrub rows around the foundation ofthe house to create an insulating dead air space.Foundation plantings, however, can represent a fire hazardif the plants are highly flammable. Likewise, trees near thehouse can create a fire hazard due to overhanging branch-es. A common energy conservation recommendation is toplant vines near a home to shade walls, another practicenot recommended in firewise guidelines.

Multiple landscaping goals

There are several landscaping programs that combine mul-tiple landscaping goals, such as the Florida Yards andNeighborhoods (FYN) program (http://edis.ifas.ufl.edu/EP079). This program emphasizes elements of the afore-mentioned landscaping goals, such as water efficiency,“right plant, right place”, mulching, and attracting wildlife.The FYN program also emphasizes recycling, reducingstormwater runoff, and protecting waterfront. Sustainabledesign guidelines, such as Low Impact Design (LID),encourage the use of native plants and minimal irrigation,

5 as well as minimizing land clearing and other site distur-bances during development. LID guidelines are part of thegreen design movement, which seeks to lessen theimpacts of development and to increase water and energyefficiency.

Apparent conflicts

Where firewise guidelines seem to conflict with other land-scaping guidelines, slight modifications can be made toovercome these apparent conflicts. This can help create aprogram that incorporates firewise and other landscapinggoals. Table 1 provides an overview of how these differentlandscaping goals (i.e. wildlife habitat creation orenhancement, water conservation, and energy conserva-tion) (in columns) agree or conflict with key firewise princi-pals (in rows). When a firewise landscaping principle iscompatible with a goal (i.e. does not conflict), there is a“Y” (yes) in that column. If a firewise landscaping princi-ple is potentially incompatible (i.e., potential for conflict)with a particular goal there is an “N” (no). The apparentconflicts will be discussed in more detail in the followingsection titled “How to Achieve Multiple Goals.

TABLE 1. Compatibility of several landscaping goals withfirewise landscaping principles. A “Y” indicates compati-bility, while an “N” indicates potential incompatibility.

4Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

Avoid flammable plants near your home

Group plants to create areas that won’t burn

Maintain vertical separation

Less maintenancerequired at greaterdistances from home

Clear dead plant materialand organic mulches near home

Maintain healthy plants

N N N

Y Y Y

N Y Y

Y Y Y

N N Y

Y Y Y

Firewise LandscapingPrinciple

Wildlife Water Energy

Landscaping Goals

5Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

How to achieve MultipleLandscaping GoalsIn this section, we include strategies for resolving apparentconflicts shown in Table 1 (indicated by “N”) among differ-ent landscaping goals so that multiple goals can beachieved simultaneously. The following bulleted list out-lines the key conflicts between firewise landscaping andother goals and suggests some solutions to overcomethese conflicts. If you are not sure of your wildfire risk, youcan determine it by completing a wildfire risk assessmenton your property (http://edis.ifas.ufl.edu/FR076 orhttp://www.interfacesouth.org/fire/WildfireRAGH.pdf ) orby contacting your county forester or extension agent forassistance.

Avoid flammable plants near your home

Conflict 1: Firewise generally discourages plantingshrubs close to a house. Foundation shrubs are recom-mended, however, for energy conservation. Energyconservation principles also promote strategic place-ment of trees near the home for shade and conse-quently reduced energy costs.

Solution 1: Foundation shrubs should have at least 2-3feet between their branches and the house and betrimmed to stay 2 feet below the windows. Selectshrub species that have a low flammability (see exten-sion publication “Selecting and maintaining firewiseplants” (http://edis.ifas.ufl.edu/FR147) for how to dothis). Also select trees of low flammability and trimbranches up to 10 feet.

Conflict 2: In firewise landscaping, individual or smallgroups of trees and shrubs can be maintained in thedefensible space (within 30 feet of house), but low-growing groundcovers are recommended as the pri-mary landscape plants. Yards with extensive lawnareas are often cited as good examples of firewiselandscaping because well-maintained lawns are rela-tively low in flammability, and they can function as abarrier to fire spread. However, landscaping principlesfor wildlife or water conservation recommend limitinglawn areas and they don’t specify using plants of lowflammability as criteria for selecting plants.

Solution 2: In high-traffic areas immediately aroundthe house, a well-maintained lawn may be the best

choice due to its resilience to foot-traffic and effective-ness as a firebreak. However, lawns can also becomeflammable when they are drought stressed. Thus, inlow-traffic areas of your yard and in the outer edges ofyour defensible space zone, lawn can be replaced withorganic mulches and alternative ground covers thatmight require little or no supplemental resources (e.g.,water, fertilizer, weed killers) (Figure 6). Plants of low-flammability should be selected that also meet wildlifeand water conservation principles. Sidewalk or stonesteps also work well. Note: Islands of plants (includingground covers) should be separated by areas that willnot burn, even in these outer edges.

Maintain vertical separation

Conflict 3: Firewise landscaping discourages verticallayering of vegetation while landscaping for wildlifeencourages it.

Solution 3: If you live in an area at high risk of wildfire,you should give priority to firewise landscaping andmaintain vertical separation (Figure 5) between plantswithin your defensible space. However, beyond thatdefensible space you can leave patches or islands ofvertically layered vegetation, as long as these islandsare separated horizontally by areas that are cleared ofdense vegetation.

Clear dead plant material and organic mulchesnear home

Conflict 4: Firewise recommends removing deadplants and brush piles from around the house, whilewildlife landscaping encourages leaving such plantmaterials as habitat for wildlife. Firewise also oftendiscourages the use of organic (or wood-based)mulches close to the house due to their potential firehazard. The use of mulches in landscaping is recom-mended for water conservation.

Solution 4: If you have a large enough lot, createsmall, isolated brush piles greater than 60 feet fromyour house and remove all dead plant materials fromwithin your defensible space with the exception ofmulches. Organic mulches composed of large chunks,such as pine bark, can be used in landscaping near thehome. Pine straw mulch is highly flammable andshould be avoided. Maintain an area 2-3 feet outwardfrom side of house as bare ground or covered by

SummaryHomeowners who are interested in landscaping to con-serve energy and water and to enhance wildlife habitat canalso make their homes safe from wildfire with proper plan-ning. When firewise landscaping is compared with otherlandscaping goals, few differences actually exist. In thoseinstances that reveal conflicts, small modifications canoften be made to resolve differences.

Currently there are landscaping programs, such as theFlorida Yards and Neighborhood program (http://edis.ifas.ufl.edu/EP079) that encourage landscaping for multipleenvironmental goals (e.g., wildlife habitat enhancement,water and energy conservation). Firewise principles couldbe similarly included with other landscaping goals byresolving apparent conflicts, as we have outlined on pages5-6. Landscaping for multiple goals, including firewise,

ensures an environmentally friendly, sustainably designedlandscape while reducing the risk that wildfire may dam-age your home.

Additional ResourcesFire

Firewise Web site (www.firewise.org). National Wildland-Urban Interface Fire Program.

Landscaping in Florida with fire in mind by M. Monroe andA. Long (http://edis.ifas.ufl.edu/FR076)

Firewise Retrofit Home on InterfaceSouth (www.interface-south.org/fire/firewisehome). The Southern Center forWildland-Urban Interface Research and Information.

Wildlife

National Wildlife Federation Backyard Wildlife Habitat pro-gram (http://www.nwf.org/backyardwildlifehabitat/index.cfm)

Landscaping backyards for wildlife: Top ten tips for successby M. Hostetler, G. Klowden, S. Miller, K. Youngentob(http://edis.ifas.ufl.edu/UW175)

Water conservation

Waterwise landscaping website by St Johns WaterManagement District, Florida. (http://www.sjrwmd.com/programs/outreach/conservation/landscape/)

Xeriscaping for Florida homes by M. Brandies, publishedby Great Outdoors Publishing Company, Inc., 1999.

Energy conservation

Landscaping for energy efficiency by U.S. Department ofEnergy. (http://www.eere.energy.gov/erec/factsheets/landscape.html)

Conserving energy with plants by M.A. Powell.(http://www.ces.ncsu.edu/depts/hort/hil/hil-631.html)

Multiple landscaping goals

A guide to environmentally friendly landscaping: FloridaYards & Neighborhood Handbook. (http://edis.ifas.ufl.edu/EP079)

6Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

rock/gravel, and keep it clean of all mulch and otherplant material. Snags are individual, dead trees, andthey can be left outside the defensible space, as longas they are not tall enough to fall on your house. Snagretention is most appropriate for larger lots, wheremore distance can be left between them and thehome. All dead branches should be removed fromthese trees within 10 feet of the ground, as should anybranches that could be hazardous to people if theywere to fall.

figure 6. The beach sunflower (Helianthus debilis) in this landscaping island isa low-growing groundcover that requires little maintenance once established.They are one example of an aesthetically pleasing alternative to the commonlawn that is water efficient and firewise.

Phot

oC

redi

t:La

rry

Kor

hnak

6

Florida guide to environmental landscaping by E. Gilman,S. Brown (http://edis.ifas.ufl.edu/EL001)

Enviroscaping by J. Bradshaw, L. Tozer(http://edis.ifas.ufl.edu/EH215)

Sustainable Design Guidelines

LEED: leadership in energy and environmental design(http://www.usgbc.org/DisplayPage.aspx?CategoryID=19&)

The practice of low impact development. Published by U.S.Department of Housing and Urban Development, 2003.(http://www.huduser.org/publications/destech/lowim-pactdevl.html)

Other fact sheets in the series “FIREIN THE WILDLAND-URBAN INTER-FACE” (http://edis.ifas.ufl.edu/)Circular 1431: Fire in the Wildland-Urban Interface:

Considering Fire in Florida's Ecosystems.

Circular 1432: Fire in the Wildland-Urban Interface: Understanding Fire Behavior.

Circular 1445: Fire in the Wildland-Urban Interface:Selecting and Maintaining Firewise Plants forLandscaping.

Circular 1453: Fire in the Wildland-Urban Interface:Preparing a Firewise Plant List for WUI Residents.

This fact sheet is available on-line on the Southern Center for Wildland-Urban Interface Research and Information’swebsite, InterfaceSouth, at http://www.interfacesouth.org/products/Reducing_Wildfire_Risk.pdf. It can also befound on the UF/IFAS EDIS website referenced above asCircular 1478.

Permissions andAcknowledgementsThe authors of this publication give permission to repro-duce this fact sheet. Cotton K. Randall, former Wildland-Urban Interface Fire Project Coordinator, School of ForestResources and Conservation, IFAS, University of Florida;L. Annie Hermansen-Báez, Center Manager, USDA Forest

Service, Southern Center for Wildland-Urban InterfaceResearch and Information; and Glenn Acomb, AssociateProfessor, Department of Landscape Architecture,University of Florida.

The development of the information in this fact sheet wasfunded by the National Fire Plan through the USDA ForestService, Southern Research Station, Southern Center forWildland-Urban Interface Research and Information.

Julissa M. Hernandez of the UF/IFAS CommunicationsServices office is acknowledged for her creative illustra-tions and for designing the layout of this publication.

For more informationor questions contact Annie Hermansen-Báez of the USDAForest Service, Southern Research Station at (352) 376-3271, ahermansen@fs.fed.us or Alan Long of the Universityof Florida at (352) 846-0891, ajl2@ufl.edu.

7Fire in the Wildland-Urban Interface: Reducing Wildfire Risk While Achieving Other Landscaping Goals

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information andother services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex,

sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service,University of Florida, IFAS, Florida A.&M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating.