The Right Landscaping Can Stop Fires

(Editor’s note: the following was written by Shawn Maestretti of Studio Petrichor for his newsletter and is reprinted with permission. He is a designer, licensed landscape architect and contractor, certified arborist, certified permaculture designer biospheric caretaker, speaker and educator. https://studio-petrichor.com/about/ His business is located in Altadena.)

I am writing to express my deep concerns regarding the current approach to defensible space laws, particularly as they relate to fire risk mitigation in urban and suburban settings.

While I appreciate the intent behind these regulations, the approach taken by Cal-Fire (CF) and other agencies overly simplifies a complex issue and risks exacerbating the very problem it aims to solve. It is my intention to share perspectives from within the firestorm, to empower communities to engage with their environment, and to highlight that these issues are not a “one-size-fits-all” approach.

Concerns with the Current Narrative (and proposed enforcements)

1. Nature as “Fuel”

Throughout Cal-Fire’s documents, vegetation is framed as “fuel,” reinforcing a divisive and harmful narrative that separates humanity from the environment. This framing incites fear rather than fostering a healthy, informed caution about fire risk. The natural landscape provides essential habitat, beauty, and planetary life support, and reducing it to mere fuel undermines the ecological balance necessary for fire preparedness.

2. Misguided Priorities

The stated goal of these regulations is to “improve safety for firefighters defending a home,” yet this was not the determining factor in the recent Eaton Fire in Altadena. In most cases homes were left to burn and a few homeowners decided to stay behind to do what they could. In other words, resources were constrained, and it was left up to us…the homeowner. Survivability of structures is the key issue, not vegetation removal. The real problem lies in the way structures are built and organized within fire-prone ecotone communities, not by the mere presence of plants and trees.

3. Flawed “Defensible Space” Concept

The term “defensible space” is misleading. Instead, the focus would best be focused on creating “defensible homes,” as it is the structures themselves that are flammable. Educating homeowners on fire-resistant building materials, proper architectural planning, and community-level strategies will be far more effective than enforcing arbitrary vegetation removal mandates.

4. Unrealistic Requirements

• The Zone 1 requirement of a 30′ setback is unfeasible for most urban and suburban homeowners.
• The Zone 0 gravel perimeter is ineffective against embers that can travel a mile or more ahead of the actual fire front during the fires that cause the most devastation – wind-driven fires, and is a further blight on our tightly knit communities.
• The removal of trees and vegetation in Zone 0, and beyond, further increases heat island effects and exacerbates drought conditions, making communities more vulnerable to extreme fire behavior and ember ignition.

5. Industry Burns Homes

These requirements disproportionately benefit for-profit industries and insurance companies while burdening everyday homeowners.

The deeper issue lies in unchecked sprawl, architectural allowances that permit building from lot line to lot line, and an economic system that prioritizes profit over community and ecological health.

Capitalism, not vegetation, is accelerating the pace and scale of destruction. By prioritizing development at the expense of ecological integrity, the industry contributes directly to the conditions that allow fire to spread rapidly through neighborhoods. It is time we recognize that systemic decisions—not gardens—are the true culprits behind catastrophic losses.

A 2021 report by Headwaters Economics found that “the majority of homes lost to wildfires are due to ignition from embers, not direct flame contact from vegetation.” Moreover, the Insurance Institute for Business & Home Safety (IBHS) underscores that “home ignition is more influenced by the home’s materials, design, and maintenance than by nearby vegetation.”

Additionally, research from the U.S. Forest Service and California Chaparral Institute confirms that land use patterns—not native plant communities—are a primary driver in fire severity and loss of structures. These findings highlight the need to shift responsibility from the natural landscape to the decisions made in planning and development.

Personal Experience & Evidence-Based Observations

During the Eaton Fire, my well-vegetated property, which was annually approved by the fire department as “in compliance,” faced an onslaught of embers. Contrary to the assumption that vegetation is the primary fire risk, the key ignition sources were:

• Open vents that allowed embers to enter the structure.
• An ignited gas main that helped fuel the fire.
• Neighboring wooden fences that acted as fire conduits.

Importantly, my home’s soil-building mulch and an 85-year-old Podocarpus tree, along with other native shrubs, played a critical role in slowing and blocking embers. Our home landscape did not set the house on fire—flammable structures and poorly designed urban layouts did.

It is also important to acknowledge that homeowner and community support in fire events is beneficial. The notion that homeowners are encouraged to leave their livelihood behind and hope for the best removes the most powerful way to help slow fires down.

At 6:30 am, my husband went back up to see what he could do after he got us to safety. In his efforts to water the neighbor’s house down and the fences, he was able to slow the fire down even more, so that other neighbors we were in contact with later that morning were able to go back up and slow down the fire on their end, which in turn spared our office.

Human engagement played a major role when the fire department was nowhere to be seen in our neighborhood.

Recommended Solutions…based on our observations

To create truly fire-resilient communities, a holistic, whole-systems approach to urban and landscape design could strive to be adopted:

Reframing the Narrative..as mindset can be fuel too!

• Stop labeling vegetation as “fuel.”
• Change “fuel modification” and “defensible space” to “fire-ready plantings” and “defensible homes.” Or something like that.

Fire-Resilient Landscaping & Community Practice

• Promote soil-building practices such as mulching to retain moisture and slow fire spread.
• In conjunction with soil-building, promote rainwater harvesting to support landscapes that endure up to 9 months without rainwater.
• Encourage fire-resistant plants and trees, both native and non-native that have been planted and nurtured for healthy success.
• Shift from one-size-fits-all zone requirements to context-sensitive, ecologically-collaborative strategies.
• Protect and maintain healthy tree canopies, as they have been shown to slow ember spread.
• Discourage unnecessary tree removal and destructive pruning practices, such as those implemented by Southern California Edison (SCE).
• Acknowledge that the best approach to design is not a top-down issue, but more of a bottom-up, emergent, Nature-based one.

Fire-Resistant Architectural and Urban Design

• Prioritize fire-resistant materials and building designs that allow embers to pass by rather than be trapped.
• Continue to challenge flammable fences, decks and other structures that are attached to homes and perhaps adopt the possibility of native shrub hedgerows between properties. This will further increase beauty, healthy, and all while helping slow embers down
• Require fire-safe vents and automatic gas shutoff valves in all homes.
• Advocate for roof sprinkler systems, perhaps neighborhood wide systems, and accessible neighborhood water supplies.
• Implement urban planning strategies that prevent structures from being built too closely together.

Community Education & Empowerment

• Provide landscape and fire education workshops.
• Support community-based fire readiness programs.
• Encourage neighborhood committees focused on fire preparedness and mutual aid.
• Secure government funding for grassroots fire resilience initiatives.

A Personal Perspective from Shawn Maestretti

Over the past six years, I have been preparing my home and garden for both fire and drought. By implementing:

• Drought-tolerant native and non-native landscaping,
• Rainwater harvesting,
• Soil-building techniques,
• Pre-charred fencing (shou sugi ban), and
• Roof sprinklers, as well as
• Ongoing, human engagement with the landscape,

The fire that threatened my home was significantly slowed. In fact, it stopped at our house on our block. Though my house ultimately succumbed, my landscape survived, and my preparations helped protect neighboring structures. My experience underscores the fact that a holistic, ecologically sound approach works.when one is engaged with the potentiality of fire, wind, and drought.

I have video evidence that our Podocarpus tree and planting in 0 zone was damaged by the house on fire, not the other way around. So, what did go wrong in Zone 0? The fence, the gas main and the vents…not the vegetation.

This is not a one-size-fits-all issue. The proposed regulations are premature and risk being counterproductive if enacted as law. Instead, we must adopt an approach that respects the intelligence of nature, fosters community resilience, and addresses fire risk through thoughtful, evidence-based design.

Furthermore, when cities choose to push the ecotone into the wild and remove precious habitat, the more fire will burn back. Our approach to Altadena will be different from the approach that La Canada and Sierra Madre will take. Much of Altadena is burned. As for the other communities ….are they ready to burn?

Shawn Maestretti, Founder and Principal

Studio Petrichor, P.C.

California Landscape Architect #6203; Nevada Landscape Architect #1016;

C-27 Contractor #952509; Arborist #WE-12184A