What to do in your garden after getting a defensible space inspection

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.

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 inches 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 feet 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 to 10 feet 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):

• Rosemary may have been planted close to your home. Because it contains oil and will ignite easily, it should not be closer than 30 feet from your home.

• Junipers were widely used decades ago in Marin because they was 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 feet of structures and 10 feet 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:

• Chipper days: Last year, Marin residents removed more than 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 reserve.chipperday.com/marin.

• 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 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: gardenplanner.calscape.org.

Sponsored by UC Cooperative Extension, the University of California Marin Master Gardeners provides science- and research-based information for Marin home gardeners. Email questions to helpdesk@marinmg.org. Attach photos for inquiries about plant pests or diseases. Please call 415-473-4910 to see when a master gardener will be at the office or drop off samples 24/7 in the sample box outside the office. To attend a gardening workshop or subscribe to Leaflet, a free quarterly e-newsletter, go to marinmg.ucanr.edu.