Fire Safe News Fire-Wise Landscaping

The Making of a Swale

Fire Safe News Fire-Wise Landscaping

Eucalyptus: Garden Friend or Fire Foe?

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 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, 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 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

Fire Safe News Fire-Wise Landscaping

MetroView March-April 2023 Edition: Fire-ey Questions …from Your Neighbors

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 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:

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‘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:
The local chapter of the California Native Plant Society ( ) has a great pamphlet which lists native plants for area landscapes. And you can narrow info down to your specific needs at

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 for “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!

Fire Safe News Fire-Wise Landscaping

What to do if a neighbor doesn’t trim trees or brush that may be a fire hazard

1. Understand when brush is a potential fire hazard

Check out the “City of San Diego Guide to Fire Safety and Brush Management for Private Property”. It is very specific about a homeowner’s responsibilities for keeping their property free of fire hazards. There are also other resources available on the resource page of our website.

2. Share information

Obviously the first step is to try to talk to you neighbor about the potential danger.  If you think it will help, we can supply you with a hard copy of the guide mentioned above for your neighbor. 

3. Offer to help

Sometimes neighbors will offer to help trim or share the cost of trimming as just the price of also making their own house safer. 

4. Last resort: report

If nothing else works, take a picture, and report the situation on San Diego’s Get It Done site, and/or call the San Diego Fire Hazard Advisor at 619-533-4444.  Complaints are private and not shared or discussed with either party. 

They can send out an inspector, although there may be a wait because there’s a limited number of inspectors serving the whole city.  If they find brush management violations, they will advise the homeowner on corrective action needed and give them time to correct the problems.  If the owner does not correct the violations within the specified time period, the city can issue a citation with fines, and potentially “forced abatement” costing hundreds of dollars.  More info:

If electrical wires are involved, contact SDGE at 1-800-411-7343.  If possible, get the “pole number” which is stamped on a silver marker on each pole. This will give them a precise location.  They have professional arborists who can assess the situation and decide if the tree or tree limbs pose a hazard.  If necessary, they will then arrange for pruning or, if a tree needs to be removed, they can recommend replacement options that won’t interfere with wires as they grow.  They even have a tree replacement program. More info at:

Fire hazards put us all at risk, not just a single homeowner.  By taking action, you are being a responsible citizen and trying to make us all safer.  

On behalf of everyone in our community, thank you for your efforts!

Community Presentations Fire Safe News Fire-Wise Landscaping

CANYONLANDS: Brush Management Guide and Video Presentation

San Diego Canyonlands: Brush Management Training for Canyon Communities

Click here to download San Diego Canyonland’s “Brush Management + Native Landscaping Resources.”

Community Presentations Fire Safe News Fire-Wise Landscaping

Master Gardener Cindy Bruecks on Fire Safe Landscaping

Click here to see the video of the Zoom Session.

Click here to download the handout Cindy references in her talk.

FireWise gardening tips from Cindy Brucks

Kensington Fire Safe Zoom presentation, 11/17/2021

FireWise Gardening Zoom was sponsored by Kensington Fire Safe, KenTal Community Association, KenTal Gardening Club, and Trees KenTal.

Fire-Wise Landscaping

Landscaping Your Home in a Fire Area

Click here to read an article about fire safe landscaping by Las Pilitas Nursery.

Fire Safe News Fire-Wise Landscaping

Reminder to Keep Your Fan Palms Trimmed

Sure, your fan palm is beautiful with its layers of drying fronds draping down the trunk. But those dried fronds ignite easily in a wildfire and spread flying embers throughout the neighborhood. Let the unprecedented fires raging through our state right now serve as a reminder to keep your fan palms trimmed up and protected from fire. You might just save your house, or your neighbor’s.

Fire-Wise Landscaping

Mulch, Flames and Gorillas?

Flying flames apparently take a likin’ to some mulches a lot more than others. For those that are interested, a 2007 study(1) on ignition rates and flame heights came to these love affair conclusions and some recommended physical separation from flammable structures:

  1. Love at first landing: Straw and pine needles caught fire the fastest – less than five seconds. Keep at least 15 feet away.
  2. Totally infatuated: Wood chips and bark nuggets had few fire-proofing characteristics; 15–30 feet separation.          
  3. Can be dangerously flirtatious – keep several feet away.     
    1. Green, closely-mowed sod can provide excellent fire-proofing.  However, when grown more than four inches or dry, it becomes as flammable as pine needles and wheat straw. 
    1. Dense, finely ground/screened materials such as garden compost and shredded bark had strong fire-proofing characteristics, however, with enough time could possibly cause other materials to ignite.
  4. But, flames can’t stand inorganic mulches! Decomposed granite, gravel and rocks are the motherlode for superior fire-proofing, especially for cozying up to flammable structures.  Only concern is  regularly removing flammable, windblown debris.

Since this was an Arizona study, we asked local landscaping expert Greg Rubin (2) for his opinion.  Here’s what he said: 

“These results seem very consistent with our experience and measurements.  Except that when the mulch is consolidated with overhead watering (within months) or naturally (years), the flame height drops to around ~2″ (consolidation limits oxygenation). A local fire marshall ran ignition tests on our gorilla hair and came back asking, ‘What kind of fire retardant are you putting in this stuff?’.  Of course, we can never guarantee a yard or home won’t burn in a firestorm, but at least these results so far have been pretty good.”

We’d never heard of gorilla hair – maybe you all are familiar with it. For those who aren’t, it’s finely-shredded redwood and western cedar tree bark, that looks remarkably like the backs of Jane Goodall’s best friends.(3) 

Let’s hope none of us ever have to deal with any romance between flying flames and our mulch!

  1. Check out the full study here:                
  2. Mr. Rubin, the 2018 San Diego Horticulturist of the Year, recently completed a five-year Navy research project on fire-resistant native landscapes. He has published two popular books on California native landscaping and his company has installed over 700+ landscapes.