Author: Judy Harrington

By Judy Beust Harrington, Co-Chair, Kensington Fire Safe

This column is your fire safe council’s effort to share answers to questions we get from community members. Send your fire-related questions to info@kensingtonfiresafe.org and we’ll do our best to find the answer!

Q: My own question this time! Lively conversation with a Master Gardener at Kensington Earth Day left me wondering, is eucalyptus the highly flammable bad-boy as we’ve been led to believe?

What’s not to love about eucalyptus trees? Wonderful shade in hot summer months? The roosts, perches, and nests they provide for raptors and other birds? The nesting material their litter supplies local alligator lizards and rat-eating gopher snakes?  Or just that these attractive, year-round green trees often smell good and have lots of medicinal uses? (1)

Too bad “some are bullies” according to local, award-winning landscaper, Greg Rubin. Their bad behavior includes crowding out often much less flammable native plants, especially with the aggressive species’ fibrous, greedy root systems that “take no prisoners.”  This includes the most prevalent blue gums, initially planted over 40,000 southern California acres starting in the mid-1800’s.  Rut Row! Now the California Invasive Plan Council (Cal-IPC ) classifies blue gums as “limited invasive“ — because their significant negative ecological impacts occur in limited areas along the California coast. (2)

Greg says he has no problem with “Eucalyptus citriodora “…beautiful, graceful, non-aggressive large form, that plays nice with our extremely delicate, complex, and non-competitive ecology.”

But back to fire safety. Bottom line: they are not native and don’t belong in our canyons. It’s all about the bark they shed.  A well-tended euc in a homeowner’s yard isn’t likely to go up in flames as fast as a wild canyon one with highly flammable detritus at the base accumulating unabated. In fact, according to a National Park Service publication on eucalyptus – “Firefighters also now realize that wildfires are almost impossible to contain in eucalyptus forests.” Want more insights? Consult the NPS Fire Management Newsletter edition on “Eucalyptus; A Complex Challenge” (3)

Moisture Matters Most

Regardless of what kind of tree or plants you put in your yard, Greg says the most important element for fire resistance is moisture. The benefit of native, drought-tolerant plants is that a little water goes a long way, and they’ll retain it better than most non-natives. Nearly two dozen properties Greg landscaped with native plants survived major area fires, without the loss of a single home!

But aside from going native, how can we increase moisture and conserve our precious water at the same time?  How about letting winter rainfall increase your ground water with a swale…big, little, mini? Why send that precious runoff into sewers to eventually muck up our rivers and waterways?  Greg cites how Dennis Mudd, creator of Calscape.org, runs swales throughout his wonderful plantings. The soil fungi in the swale moves the moisture over to his drought tolerant plantings and greatly reduces the need for watering.  That’s because you put compost in the swale and the bacteria in it will over time help break up the clay in the surrounding areas.

I recently put a swale in my front yard to catch the overflow from one of our rain barrels – which starts flowing in 5-10 minutes during a downpour.  Now I’m making small ones wherever there’s a low patch where I plan to garden.  YouTube has plenty of videos on how to build a swale, but you can check out what I did with pictures at kensingtonfiresafe.org. Have a swale time working on yours!

Read Judy’s post about creating a small swale in her Kensington garden.

Sitting in my swale…Judy Harrington

1. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=67348
2. https://calag.ucanr.edu/Archive/?article=ca.v070n01p39
3. https://www.nps.gov/pore/learn/management/upload/firemanagement_fireeducation_newsletter_eucalyptus.pdf
4. https://milliontrees.me/2014/07/21/tracking-down-the-truth-about-blue-gum-eucalyptus/

Coif Your Canyon to Reduce Erosion and Flammability
By Judy Beust Harrington, Co-Chair, Kensington Fire Safe
Photo Credit (Above): Lucy Warren

This column is your fire safe council’s effort to share answers to questions we get from community members. Send your fire-related questions to info@kensingtonfiresafe.org and we’ll do our best to find the answer!

Q: From Loren, an Alder Circle resident: “What should I plant in my shaded, bare dirt canyon area, to reduce fire and erosion risk?”

A: There was a house on Alder they called the sliding shame… I’m told the back room went right down the canyon decades ago in a heavy rain, probably like ones we witnessed this past winter. This neighbor’s question is timely!

Lists of online drought and fire-resistant plants seem overwhelming, so I reached out to Kensington resident and UC Cooperative Extension Master Gardener, DeLayne Harmon, and she reached out to fellow MGer, Lucy Warren, a southern California sustainable landscaping expert and writer. (Check out her excellent “California Native Plants” video at: https://www.youtube.com/watch?v=6K_0mj4h548.)

Lucy’s advice? “My personal one-plant response for slopes: Baccharis ‘Pigeon Point’ mixed with at least four other species.”
“Coyote Bush” – as it is also called – is a favorite of your fire safe council! Not only is it fast-growing, drought-tolerant and slope-stabilizing, it also is said to emit a mild flame retardant when faced with a fire. And, while it prefers sun, it can grow in mostly shade too.

DeLayne clarified that Pigeon Point ground cover – Baccharis pilularis spp pilularis – is a specific coyote bush hybrid with smaller leaves that only grows to about two feet. You can often find it at City Farmers Nursery (3110 Euclid) or Hunter’s Nursery (3110 Sweetwater Road, Lemon Grove). More info at Calscape.org: https://calscape.org/Baccharis-pilularis-ssp.-pilularis-‘Pigeon-Point’-(Pigeon-Point-Coyote-Brush)?srchcr=sc5e39ba57165f9

Be a Diversity Diva

What about that “four other species” advice? Check out Lucy’s co-author and popular local landscaper, Greg Rubin’s website on the role of native landscaping in fire suppression. Greg has landscaped homes that came out relatively unharmed while nearby houses were destroyed in wildfires. His years of research for the U.S Navy established that lightly hydrated evergreen, perennial native plants assist in fire suppression as well or better than succulent plants. And diversity can help fight diseases too. More info at Greg’s CalOwn website: https://www.calown.com/nativeEcology_fireSafety.html
The local chapter of the California Native Plant Society (https://www.cnpssd.org/ ) has a great pamphlet which lists native plants for area landscapes. And you can narrow info down to your specific needs at gardenplanner.calscape.org.

Plant water!

Another way you might increase your canyon’s erosion and fire resistance is to capture some of the mountains of water that run off your house, with rain barrels and “swales” to safely catch the barrel’s overflow during our rainy season. Swales are basically flat ditches or gutters, which can be filled with rocks, compost, and plants to safely increase your ground water and keep established plants healthy. They can slow a fire’s spread toward your house and keep your trees alive if the day ever comes when we’re prohibited from using scarce water for gardens. Much swale how-to info is available online or search permaculturenew.org for “mini-swales in an urban backyard.” (https://www.permaculturenews.org/2016/01/11/mini-swales-in-an-urban-backyard/).

Bottom line for fire and erosion resistance: no to any dry woody stems, like ice plant, no to invasives like Pampas grass or leaving the ground bare. Yes to harvesting barrels of rainfall to support oodles of attractive native plant diversity! Matchy-matchy is out in jewelry and gardens!