Firewise. Waterwise.

Choose Your Plants Wisely

Fire-Smart landscaping uses carefully chosen and well maintained plants that are strategically planted to resist the spread of fire to your home. To create a Fire-Smart landscape, maintenance and design are often more important than the plant species itself. That said, some "fire-hazardous" plants burn readily, and should be avoided in residential landscaping.

FIRE SMART PLANTING

Fire-Smart planting is the cornerstone of a home's Defensible Space. Remember that all plants will burn if poorly maintained. Choose preferred species, maintain plant and soil health, irrigate appropriate to the species and location, and remove all dead material regularly.

Unfortunately, there are no “fireproof ” plants. Any plant will burn if exposed to enough heat for a long enough period of time. There are, however, considerable differences among plants in regard to being a fire hazard. Some plants are harder to ignite, generate less heat when burning, and produce shorter flames than other plants. These differences can be attributed to both inherent characteristics, such as naturally occurring differences among plant species, and cultural practices, such as pruning and irrigation.

Be cautious of the claims of plants with a “firesafe” label. Bethke et. al (2016) reviewed 20 years of plant testing studies and determined that across the board there is “no consistent standardized plant flammability testing or criteria for rating”. There are problems with definitions, types of testing, confusion between common and species names, consistency of plant care, and lack of testing across regions and climate areas. As a result, it is better to focus on characteristics of the desired plant and the location where the plant will be placed over a theoretical fire-resistant rating.

Characteristics of Fire Smart Plantings

Fire Safe PlantsFire-Smart planting requires careful plant selection, placement, spacing, and maintenance to help resist ignition and the spread of fire to your home. Fire-Smart plants are usually easier to maintain, don't contain volatile oils, accumulate less dead woody material, and are more naturally resistant to igniting from flames and embers. These plants are NOT “fireproof” and all require irrigation and frequent maintenance to resist ignition.

FIRE-SMART PLANT CHARACTERISTICS

  • Tend to have leaves, not needles.
  • 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' or lower) with minimal buildup of dead material.
  • Taller shrubs are clean, not bushy or twiggy.
  • Sap is water-like and typically does not have a strong odor.
  • Most fire-resistant trees are broad-leaf deciduous (lose their leaves), but some thick-leaf evergreens are also fire-resistant.
  • Most have lower surface-area to volume ratios.

The good news is, you don’t need a lot of money to make your landscape more fire-resilient.  Fire-Smart landscaping can increase property value and conserve water while beautifying your home.

Learn about the history of FIRESafe MARIN's plant recommendations.

Choosing appropriate Plants

  • Use the Fire-Smart Plant List for Marin county as a reference for plants suitable for Marin's climate.
  • There are no “fire-proof” plants. All plants must be maintained in good health, properly irrigated, and kept free of dead material, dry twigs, or fallen leaves and needles.
  • Select appropriate plants for hedges, which may help catch wind-blown embers if properly spaced and maintained.
  • Plant hardwood trees, like maple, poplar and cherry that are less combustible than conifers like pine and fir.
  • Maintain your trees carefully, being sure to limb up and remove "ladder fules" and shrubs beneath trees.
  • Our list of plants is curated for plants favorable to Marin's climate.  Considerations like ease of maintenance, lack pof volatile oils, drought tolerance, and non-invasive status are also part of the selection process. This list is not exhaustive: other online resources are available to help you select additional species.
    • Cal Poly and CAL FIRE publish the excellent "SelecTree" database, which can be filtered to show additional fire-resistant species.  They list 178 fire-resistant tree species for Marin's climate zones (Sunset Zones 15, 16, 17), vs the 20 trees we've selected.

Trees

Fire Safe PlantsChoose broad-leaf deciduous (lose their leaves) or thick leafed evergreen trees instead of conifers.

Shrubs

Fire Safe PlantsChoose shrubs that are low growning, with minimal dead material and supple leaves.

Hedges &Screens

Fire Safe PlantsChoose hedge and screen plants with broad, waxy leaves and that don't build up dead material.


FIRE-HAZARDOUS PLANTS

Some plants are particularly susceptible to fire: they may ignite readily and burn intensely, and should be removed or aggressively maintained if present near a home, road, or driveway. You may be required to remove some or all of these species depending on local fire codes if present within 100’ of structures. 

FIRE-Hazardous PLANT CHARACTERISTICS

Fire Safe PlantsIt is best to identify fire-hazardous plants by their characteristics,  structure, and maintenance. This is not an exhaustive list, and some plants not listed here may present a fire hazard when drought stressed or poorly maintained. Any plant in poor health, lacking irrigation, or with a buildup of dry or dead material may burn. Most common fire-hazardous plants typically share certain characteristics:

  • They are often blade-leaf or needle-leaf evergreens.
  • They often have stiff, woody, small or fine, lacey leaves.
  • Their leaves and wood often contain volatile waxes, fats, terpenes or oils (crushed leaves will have strong odors).
  • Their sap is often gummy, resinous and has a strong odor.
  • They often contain plentiful fine, twiggy, dry or dead materials.
  • They may have pubescent (hair covered) leaves.
  • They may have loose or papery bark.
  • These plants typically flame (not smolder) when preheated and ignited with a match.

FLAMMABILITY & CONDITION

The condition of the plant is often as  important as its species. Many fire-hazardous plants can be relatively ignition-resistant if properly maintained and irrigated, especially natives.  Depending on its growth form and access to water, the same species may be ignition resistant in one environment and flammable in another.  Water-stressed plants in poor condition are more likely to burn readily. Those species already identified as fire-hazardous may become explosively flammable when poorly maintained.  South-facing slopes, windy areas, sites with poor soils and urban landscapes are more stressful for plants and often lead to greater hazard from burning vegetation.

COMMON FIRE-Hazardous VEGETATION TYPES

  • Grasses: Any cured (dry) grass, including bamboo. Non-irrigated, annual grasses are typically more flammable than perennial grasses. Irrigated grasses are fire resistant.
  • Perennials and herbs: Any dry or cured herb.
  • Ferns: Any dry or cured fern, particularly bracken and sword ferns.
  • Brush: Any brush with excessive deadwood. Any over-mature, dying or dead brush.
  • Trees: Any forest, stand or urban forest that is over-dense, under stress, poorly maintained, or over mature.

Some Plants Were Made to Burn

Many plants are particularly susceptible to fire. Some plants ignite readily and burn intensely, and should be removed if present in a home's Defensible Space zones or close to roads and driveways.

Juniper

Fire Safe PlantsJuniper is a common landscaping plant in Marin. Deceptively green, it is often planted along patways and driveways, a recipe for disaster when a homeowner finds their escape blocked by a wall of flames. Juniper should be removed within 30' of structures, and 15' of driveways or roadways.

Bamboo

Fire Safe PlantsBamboo are fast growing grass species that can make a good privacy screen - as long as you live in outside the Wildland Urban Interface (WUI). Although some species of bamboo can be maintained in a relatively fire resistant state, their rapid moisture loss during periods of hot, dry weather and tendency to accumulate fine, dead leaf litter makes them unsuitable as a screening plant near homes. If you live in or near the WUI, choose fire-resistant screens and hedges instead.

Cypress, Thuja, Arborvitae

Fire Safe PlantsThese evergreen conifers are valued for their screening properties and low maintenance. Like juniper, they may be explosively flammable, and don't belong in the landscaping around homes in Marin's Wildland Urban Interface.

Italian Cypress

Fire Safe PlantsItalian cypress are often planted as an architectural compliment to mediterranean-style homes.  These tall, highly combustible trees are sometimes referred to as "Roman candles" by firefighters.  With a structure that is difficult to maintain free of dead woodly material and dry needles, they ignite easily. They should be removed or avoided in or near the Wildland Urban Interface (WUI).  Watch Italian cypress burning on FIRESafe MARIN's YouTube channel...

FIRESafe MARIN first published a list of common "fire prone" plants in 1998. This list, created with the help of the University of California Cooperative Extension (UCCE), was later adopted by the County of Marin and all Marin Cities and Towns for their Fire Standards, expressly prohibiting the planting of these species for new home and remodel construction, and limiting thier use in existing landscaping. This list has evolved over the years, to encourage the use of properly maintained native plants, limit the spread of invasives, and better inform homeowners. Fire inspectors may require removal of existing plants on this list, or any plant that presents a hazard, if they threaten your home or neighbors.  It has been revised extensively based on 30 years of observations and experience, and is now maintained by FIRESafe MARIN as  a "fire-hazardous" plant list (with slightly differtent meaning). The UCCE no longer teaches from lists, preferring to instead teach the characteristincs of plants that contribute to wildfires - but FIRESafe MARIN continues to see a value in providing homeowners examples of commong fire-hazardous plants.

In Marin, It's The Law

In Marin, the County, Cities and Towns have all adopted variations of Defensible Space ordinances for homes in the Wildland Urban Interface (WUI). Modeled after the State Law but with even greater restrictions, the plants listed here as fire prone can not be planted in a home's Defensible Space zone (100' from structures). Your fire department may require removal of plants on this list if they threaten your home or a neighbor. If you buy one of these plants for your garden, you may just be burning money...

Need advice?

Call us at (415) 570-4FSM {4376}
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Don't forget to bring a copy of our Fire Safe Plant List to your local nursery!

FIRESafe MARIN   |   P.O. Box 2831  |   San Anselmo, CA 94979   |   info@firesafemarin.org

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