Flowers bloom and vegetation returns near a building under construction in Altadena next to where a house was destroyed in the 2025 Eaton Fire. (Photo by David McNew/Getty Images)
IN 1921, THE WRITER AND TOWN PROMOTER WILLIAM E. SMYTHE published a book whose philosophy would endure in Los Angeles as perhaps nowhere else in the world. City Homes on Country Lanes called on Americans to reject the crowded, industrialized cities of the East in favor of “a little land and a living” out West, where an acre could be bought for cheap and a family could grow their own sustenance.
This didn’t have to mean going rural. “Garden homes,” as Smythe called the dwellings he imagined, could be built in urban areas or even constitute them like in Southern California, where a green metropolis was growing: “It is there that the largest number of people have seen the light and gone farthest along the new path,” he wrote.
Smythe filled his book with illustrations of what a garden home could look like. In one diagram, a five-room bungalow on a ⅙-acre lot — “the standard-sized lot in Los Angeles” — sits draped in flowering vines and surrounded by rose bushes, vegetable beds and fruit trees. Behind the garage is a blackberry bramble, chicken coops and rabbit hutches.
An illustration from William E. Smythe’s City Homes on Country Lanes. (City Homes on Country Lanes via the Internet Archive)
A century later, you don’t have to be an aspiring homesteader to see how this image represents what is still an L.A. platonic ideal: A little house with a lush yard, taking full advantage of the sun. The ubiquity of properties like these is partly why L.A. is so bereft of public parks. That history also helps explain why L.A. has been a hotbed of opposition to California's “zone zero” rules, a set of proposed wildfire safety regulations designed to create more defensible space around high-risk homes through, among other things, the removal of vegetation.
As fires have become more common and catastrophic in the era of climate change, the state of California has sought policy solutions to protect communities against the flames. The concept of zone zero — which refers to the first five feet surrounding homes and structures in high wildfire risk parts of the state — has recently been at the forefront of those discussions. But the push to regulate those areas has also been extremely controversial, particularly in L.A., where some residents and scientists have resisted the state’s calls to pare back on home greenery.
After years of wrangling, a state board released revised zone zero rules on April 17 that suggest L.A.’s garden defenders gained meaningful ground in their fight, disappointing those who’d like to see more stringent rules adopted.
In the coming months, the board is expected to finalize the regulations, which are meant to help shield communities against the threat of megafires. Yet some critics argue that zone zero’s latest plant-related provisions still rest on shaky science — a debate that will continue to play out for years to come.
A bit of background: A state law passed in 2020 directed the California Board of Forestry & Fire Protection to develop zone zero rules for creating new defensible space within the first five feet of homes and structures in high wildfire risk areas. (Existing rules already apply to zone one, or the first 30 feet around a building, and zone two, the area between 30 and 100 feet.) The goal is to keep the space immediately around a house free of any combustibles that could ignite should wind blow embers onto the property. After years of delays and missed deadlines by the board, Governor Gavin Newsom signed an executive order rebooting the rulemaking process in the wake of L.A.’s devastating fires in January 2025. State and local fire agencies would be responsible for enforcement. The board has stressed that the “goal is not to penalize property owners” but rather to educate and encourage implementation.
A diagram of the zones. (California Board of Forestry & Fire Protection)
Last March, the board issued draft rules that would require homeowners to tear out most vegetation in the five-foot zone, including shrubs, grass and mulch. Plants in non-flammable pots were OK, as were tall trees, so long as low-lying branches were pared back and the roof and gutter cleared of dead needles and leaves. Lumber, storage sheds, wooden fences and most other combustibles in the five-foot zone would also need to go.
But the green stuff has been the big point of controversy.
Those in favor of the regulations argue that plants growing alongside a house should be removed, because flying embers can slam into a wall and collect at its base, potentially igniting anything flammable there (like a hedge or ferns) and exposing the house — particularly any overhanging eaves — to flame.
“I don't think it's a crusade against plants. The idea is to just push back anything that can possibly burn a little bit,” says Michael Gollner, a professor of mechanical engineering who studies fire science at the University of California, Berkeley. Gollner’s research has modeled that if all homeowners in a given area removed all combustibles within zone zero, it could reduce structure loss in a major fire by 17%.
But after the tough rules dropped last year, a number of L.A. residents — including some victims of the Palisades and Eaton fires — showed up to the board’s public workshops to defend their landscaping, which many held blameless in the disasters. “My home and my neighbors' homes burned because of adjacent structures, not vegetation,” Jessica Rogers, the president of the Pacific Palisades Residents Association, told the board in September.
Another common refrain: That well-hydrated vegetation can potentially help insulate a house from fire and provide essential cooling, shade and wildlife habitat the rest of the time. Some L.A. City Council members shared these critiques, and earlier this year the council moved to develop a set of more lenient zone zero rules allowing for healthy vegetation.
The state board also took the uproar seriously, and its latest revision of the zone zero rules is something of a compromise.
The new plan would roll out in two phases: Within three years, homeowners would have to remove firewood, dead leaves and branches, mulch and wood chips within five feet of the structure. Within five years, they’d have to create an “under-eave safety zone” clearing out any combustibles — such as wood fencing, as well as most plants — within the first foot or so of the house. But notably, local jurisdictions will now be able to tailor the safety zone rules to their communities and come up with alternatives, “provided they achieve equivalent fire safety outcomes,” according to a board news release.
That means it’s possible L.A. will end up allowing healthy plants throughout zone zero, while other California communities — such as Berkeley, which has already adopted strict five-foot vegetation removal rules for hillside homes — will not.
“If Berkeley wants to threaten homeowners with jail if they don’t clear their bushes, that’s Berkeley’s to do,” says David “Lefty” Lefkowith, president of the Mandeville Canyon Association, a homeowners’ association in West Los Angeles. “We’ll do it differently.”
A vocal critic of the state’s rulemaking process, Lefkowith says he is largely pleased with the board’s latest draft because of its emphasis on local control. (Berkeley’s enforcement of its zone zero rules involves citations, not jail.)
What remains debated, even as the proposed regulations shift, is the science.
For Travis Longcore, senior associate director at the UCLA Institute of the Environment and Sustainability and president of the Bel Air-Beverly Crest Neighborhood Council, the issue isn’t that plants abutting homes can’t ever fuel fires; instead, it’s a question of whether that’s important in the type of wind-driven fires that raged across L.A. last year, something science lacks clear answers to.
Studies have shown that features such as wooden fences, eaves, vents and tight spacing between homes strongly influence whether a structure will burn in the event of a fire. If that was also true of healthy, non-dried out plants, Longcore says, “we should see a strong signal when we look at structure survival and try to isolate the effects of greenery in the first five or ten feet of a house.” Instead, “it just doesn't emerge as being important.” Without strong data, he thinks it’s wrong to force homeowners to tear out vegetation that provides important ecological benefits.
Yana Valavokich, a scientist with the University of California Division of Agriculture and Natural Resources and a technical advisor to the state board, counters that all plants, even well-hydrated ones, will eventually ignite under fire weather conditions, when temperatures are high and winds are strong. And she points out that the complexity and variability of fire dynamics — not to mention home design and yard maintenance — makes it extremely hard to say under what circumstances plants could offer protection.
That’s why the state’s defensible space rules are broad, she says: “They apply to all the different ways that we live.” Homeowners can’t do much to move their houses away from their neighbors, which would be a useful intervention, according to Valavokich. But the zone zero rules offer a chance to reduce risk in other ways.
Meanwhile, more research is underway. Longcore is working on a study using machine learning to analyze how trees and shrubs in zone zero influenced whether structures survived in the Palisades and Eaton fires. Another UCLA-based team has been out in those burn scars conducting field work for a separate project studying whether healthy trees can protect homes from fire.
Gollner, at Berkeley, is also continuing to study California’s resilience to fire, including with respect to the flammability of different plant species and the impact of community mitigation efforts. Given the city’s recent disasters, he finds the zone-zero pushback coming out of L.A. to be counterintuitive. “We are going to have to be careful how we implement local exceptions,” he said in an email, referring to the state’s new rules. But he hopes the board’s compromise means homeowners will be more likely to actually follow the rules. “I'd rather we do something rather than nothing.”
In other words, it will still be a while before Angelenos get the final word on what they need to do to protect their homes and how those rules will be enforced. And there will likely be plenty more political and scientific debate.
L.A. was built as a “city in the garden,” Longcore says. We’re just beginning to understand — and deal with — the consequences.
Laura Bliss is a writer and editor based in San Francisco.
