Creating Defensible Space

May is Nevada Wildfire Awareness Month. During this time, firefighting agencies and University of Nevada Cooperative Extension encourage Nevadan’s living in wildfire-prone areas to take action to reduce the threat to their homes. This year’s theme is “Create Unity, Fire-Adapt Your Community.” An important action that residents can take to improve house survival during wildfire and help adapt their community to fire is to create an effective defensible space. When entire neighborhoods unite to create defensible space for all their properties, they can reduce the wildfire threat to their whole community.


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Defensible space is the area between a house and an oncoming wildfire where the vegetation is managed to reduce the wildfire threat and allow firefighters to safely operate. If firefighters are not present, defensible space improves the likelihood that a home will survive without their assistance. Many homeowners are unsure how to create defensible space. Cooperative Extension’s Living With Fire Program identified five fundamental concepts to creating defensible space:


#1 Know Your Distance: The size of defensible space is often expressed as the distance extending outward from the footprint of the house. The recommended distance is not the same for every property, but varies according to steepness of slope and type of wildland vegetation present. For flat, grassy areas, 30 feet is adequate. On steeper ground covered with dense brush, 100 feet or more may be necessary. If the recommended defensible space distance exceeds your property boundary, seek permission from adjacent landowners before doing work on their properties.


#2 Remove Dead Vegetation: Remove dead vegetation within the recommended defensible space area. Dead vegetation has a significant influence on fire behavior and can be easily ignited by embers produced from a wildfire. Dead vegetation includes dried grass and weeds, dead and dying shrubs and trees, dead branches and dead needles and leaves.


#3 Create Separation: Thin dense stands of brush and trees within the recommended defensible space distance. As a rule of thumb, remove individual shrubs, such as sagebrush, and pinyon and Utah juniper trees, to create a separation distance of about twice the plant’s height between plants. For other trees, provide a separation of at least 10 feet between tree crowns and between tree crowns and houses.


#4 No Ladder Fuels: Vegetation that can carry a fire from low-growing plants to taller plants is called “ladder fuel.” Lower tree branches should be removed to a height of at least 10 feet above ground. However, do not remove more than one-third of the tree crown. Also, remove shorter trees and shrubs from under the drip line of the tree canopy.


#5 Make It Lean, Clean and Green: Within at least 30 feet of the house, emphasize use of irrigated herbaceous plant materials such as lawn, flowers and succulents, and noncombustible landscape surfaces such as  gravel, concrete and pavers. Do not use wood mulches within 5 feet of the house or in a widespread manner within 30 feet. Shredded rubber mulch and evergreen shrubs like ornamental junipers are not recommended for use in this area.


For more information and to view a calendar of Nevada Wildfire Awareness Month events, visit


Ed Smith is a natural resource specialist with University of Nevada Cooperative Extension. For information about gardening and landscaping, contact a master gardener at 775-336-0265 or