Marin IJ Articles

I got my defensible space inspection; now what should I do in my garden?

• Julie McMillan

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  Plant natives such as Clarkia amoeba which need less water and attract pollinators. Photo: Bonnie Marks

  Again this year, the Marin Wildfire Prevention Authority (MWPA) will conduct more than 30,000 defensible space inspections of Marin residences to determine whether properties meet wildland-urban interface (WUI) defensible space, vegetation management, and construction standards. If you received an inspection, you may be asking: Now, what should I do in my garden? 

  Review your inspection results by accessing the comments online for detailed information identifying concerns and recommendations. Generally, the most common landscape issues fall into three categories: improving maintenance, pruning trees, and removing certain plants. Take advantage of MWPA programs for assistance: free Chipper Days and resident grant funding. Finally, choose native plants to replace plants you need to remove.

  

  Junipers called “gasoline bushes” should be removed (some jurisdictions require this). Photo: Fire Safe Marin

  Fire starts when oxygen and heat come into contact with fuel. Fuel is anything that burns, so that’s why you need to remove leaves, needles, grasses, and weeds, as they act as conveyors for embers to ignite your home. The most common maintenance concerns are leaf and needle litter on roofs (gutters, eaves, vents, and chimneys) and on the ground, along with grasses and weeds. Remove leaves and needles from all areas on your roof (or get help). Rake up leaves and needles. Trim grasses to 4” or lower and remove weeds. Do maintenance year-round.

  To make your trees fire-safe, remove all branches overhanging your home. Trees and branches should be at least 10’ away from structures. Remove the “ladder fuel” that a fire could use to reach your trees’ canopies (and then spread the fire) by limbing up trees 6-10’ from the ground or up to one-third of their height. Cut out dead, diseased, and dried wood, as these areas will easily catch fire.

  Although all plants burn, inspectors recommend removing plants that contain waxes, oils, and resins or that have an open-growth structure that captures debris, making them more likely to ignite. Inspectors have been identifying the following plants, along with others, for removal (some Marin jurisdictions also have ordinances requiring removal): 

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    Remove Italian cypress, or “Roman candles”; they catch on fire easily, exploding and spraying embers. Photo: Fire Safe Marin
    Rosemary may have been planted close to your home. Because it contains oil and will ignite easily, it should not be closer than 30’ from your home. 
  • Junipers were widely used decades ago in Marin because they were considered one of the hardiest, most versatile, and drought-tolerant shrubs. Now, firefighters refer to junipers as “gasoline bushes” as they contain oil, collect debris, and burn easily. Remove them within 100’ of structures and 10’ of roads and driveways. 
  • Italian cypress was often added as an architectural complement to Mediterranean-style homes in Marin. Now, firefighters call them “Roman candles” because they are difficult to keep free of dead woody material and dry needles, ignite easily, and literally explode, increasing and intensifying a wildfire. 
  • Bamboo, a fast-growing grass species, may seem like a good privacy screen, but not in the WUI. Bamboo loses moisture rapidly during hot, dry weather and accumulates fine, dead leaf litter, making it unsuitable near homes. 

  
  Take advantage of MWPA programs to help address your landscaping issues: 

  1. Chipper Days: Last year, Marin residents removed over 10,500 cubic yards of vegetation from their homes with this free program. This year, the MWPA is providing even more Chipper Days throughout the year. MWPA personnel will bring equipment to your curb to chip and remove your debris, again for free. Sign up and follow the requirements at https://reserve.chipperday.com/marin. 
  2. Resident Grant Program: The MWPA offers grants of up to $1,000 for vegetation work identified in your defensible space inspection for eligible Marin recipients. To learn more, please visit: https://www.marinwildfire.org/resident-info/resident-grants

  
  After you remove the plants identified in your defensible space inspection, what should you replace them with? Native plants are best: they need less water, attract pollinators, and are more fire resilient. Here’s an easy and fun tool to help you find native plants you like that are also well-suited for your garden’s microclimate: https://gardenplanner.calscape.org.