- Author: Luca Carmignani
How can weed control help with wildfire preparedness?
Wildfires are part of California's ecosystems, and they do not have to lead to the destruction of structures and livelihoods. Each of us can contribute to improving wildfire resilience, from individual homeowners and businesses to entire communities. Managing the vegetation and landscape around our homes can play a crucial role in preventing the spread of fires and sources of ignition.
Given the large amount of rain in the winter of 2022-2023, you might have experienced a surge in annual grasses and fast-growing plants that cover most of the ground around your home and community. In my area, I observed invasive species like wild oats and mustard growing rapidly in the spring, then drying out as summer approached (Figure 1). Dry vegetation poses a major threat to our homes and communities, both in terms of ignition (possibility of starting a fire) and fire path (creating ways for a fire to spread).
Understand fire risks.
Fires require fuel to spread, and any combustible materials, including vegetation, wooden fences, or sheds can serve as fuel. Once ignited, these materials can create a direct fire path toward a residence. Fires also generate embers (small fuel brands transported by the fire plume or wind) that can ignite leaves or debris on roofs and gutters or penetrate directly into a building through vents. Embers can also accumulate near the house, especially within the first 5 feet. You can reduce your home's exposure to flames and embers by implementing defensible space and home hardening strategies. Creating a defensible space involves managing the landscape around buildings (such as houses, sheds, detached garages) to prevent fires from reaching them. Home hardening focuses on improving building components, such as vents, roofs, and gutters, that could reduce exposure to flame and ember ignition. Though it can seem overwhelming to figure out where to begin reducing your home's fire risk, in this article I will walk you through a few simple, cost-effective recommendations that have been shown to make a difference.
Fires can start from weeds.
How do we build a fire in a firepit? We start by adding the smaller kindling, and then the larger pieces of wood. Why? Because twigs and small branches are easy to ignite, they burn quickly, and they can be used to ignite larger logs. Similarly, dry grasses and herbaceous plants are easier to ignite than other types of vegetation such as big shrubs or trees.
Weeds can be ignited directly by flames, or by embers and sparks landing nearby. A mower hitting a rock or sparks from a power tool can easily ignite dry grasses around your property. Using the firepit analogy, ground fuels such as weeds serve as kindling to spread the fire to larger fuels nearby such as fences, decks, and shrubs. Therefore, removing weeds from vulnerable locations, such as near fences (Figure 2), is a very effective way to prevent ignitions around homes and communities, and reduce potential fire paths. It's easier to remove weeds while they are still green. This reduces the risk of ignition caused by mowers and prevents invasive species from reaching maturity and producing viable seeds.
Weeds and fire paths.
In addition to being easy to ignite, dry grass and herbaceous plants can also create fuel continuity. Fuel continuity, or fire path, refers to the way a fire could spread toward a building. There can be both horizontal and vertical paths (Figure 3). Weeds can provide horizontal continuity between shrubs or other combustible materials, increasing the intensity of a fire and bringing it closer to the house. Thus, it is important to create horizontal separations between groups of plants when maintaining vegetation. When burning grass ignites a fence, the fire “climbs up” from the ground, and if the fence is attached to the house, the fire can continue to climb. A fire can reach a building by using this vertical path, often called a “fuel ladder.” The risk of fire spreading to your house can be significantly reduced by removing these potential fire paths, starting with ground fuels like annual grass. However, other sources of ignition, such as embers, may create additional paths. It is therefore crucial to harden house components like vents (for example, by replacing their screens with a metal mesh of 1/8” or smaller) and keep your roof and gutters clean.
What can you do?
Maintaining the landscape and vegetation around your home and community is crucial to preventing losses during a wildfire. Prioritize your actions to reduce the risk of ignition and fire spread around your home starting from the building and working outwards. Below are some recommended actions for creating and maintaining a fire-resilient landscape:
- Remove annual weeds and litter from vulnerable locations such as fences, sheds, siding, and under decks.
- When mowing or removing grass, be careful of sparks from power tools or other machinery, especially near open areas. Make sure you have access to water in case of a fire emergency.
- Break horizontal and vertical fire paths by removing weeds and other vegetation that are easy to ignite (grass, dead twigs, and dry leaves).
- Prune lower branches of shrubs closer to the ground and clean their understory; trim lower limbs of trees that are close to other plants or buildings.
- Mulch can be effective for weed control, but it is also flammable. Do not place mulch in vulnerable locations within the first 5 feet around a structure.
- A fence creates a direct path for fires. If your fence is attached to your house, replace the last 5 feet with a noncombustible section or gate.
- Install metallic 1/8" mesh screens on vents to prevent ember entry.
- Regularly clean roofs and gutters, especially near roof intersections.
- Maintain your landscape throughout the year.
Preventing the ignition of your home during a wildfire is possible, but it requires a combination of home hardening and defensible space strategies. For more information related to wildfire preparedness, check the additional resources below:
- UC ANR Fire website: https://ucanr.edu/sites/fire/
- Reducing the vulnerability of buildings to wildfire: Vegetation and Landscaping Guidance: https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8695#FullDescription
- Wildfire home retrofit guide: https://www.readyforwildfire.org/wp-content/uploads/Wildfire_Home_Retrfit_Guide-1.26.21.pdf
- Combustibility of landscaping mulches: https://naes.agnt.unr.edu/PMS/Pubs/1510_2011_95.pdf
- Landscaping and home hardening: https://defensiblespace.org/
[Originally featured in the Summer 2023 issue of UC IPM's Home & Garden Pest Newsletter]
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- Author: Yana Valachovic, UC Cooperative Extension Advisor
A wildfire shockwave recently hit California. Maybe you missed it. While there were no large wildfires threatening homes, and the air wasn't thick with smoke like in the Northeast from the wildfires in Canada, a shockwave did hit.
State Farm, California's largest home insurance company, issued an emergency declaration. As I write this, I note that my homeowner's policy is with State Farm, and while this may not affect me today, it could affect me when I choose to sell my home or buy a new one.
State Farm announced they will stop issuing new home insurance policies. Allstate issued a similar policy last year. These actions, in essence, shrink the available pool of insurers in California and are a very troubling sign for all of us. Furthermore, this action may significantly lengthen the time it takes to sell or buy a home in California or may affect our long-term ability to sell in the future and capture the financial values we have in our properties.
The loss of over 43,000 structures to wildfire over the last 10 years has not gone unnoticed by the insurance industry. Increasing fire hazards and skyrocketing costs to rebuild has everyone on notice that business-as-usual is not working.
California's policymakers and the Insurance Commissioner have their hands full with structuring the insurance market, creating a market that manages risk and attracts a diversified pool of insurance carriers, stabilizing insurance availability and affordability, and supporting the real estate sector of California's economy.
As a member of the state's Risk Modeling Workgroup, I can tell you that many approaches are being debated to address our challenges, including 1) allowing reinsurance calculations to be a part of insurance rates, 2) finding other ways to fund the Fair Plan (California's insurance plan of last resort), and 3) allowing catastrophe models to forecast risk in order to better anticipate future losses. With the passage of Proposition 103 in 1988, rate setting has been driven by past claims experience. Most suggest that future losses are likely to be significantly worse than past losses.
On July 13, the California Insurance Commissioner will hold a public hearing on whether rates should utilize catastrophe models that can account for anticipated climate changes and risk mitigation actions taken by property owners. Further, the state's Risk Modeling Workgroup will issue a report on this topic later this summer.
While these approaches are nuanced and complicated to understand, there are many actions that property owners can take to protect the value of their properties and mitigate risks.
Given this period of insurance instability, the best action property owners can take is to understand and mitigate wildfire risks. Reducing fuels, improving defensible space, and hardening the exterior of their structures to heat, flame and ember exposures will help to entice insurance companies to underwrite your property, enhance the ability to sell the property, and improve the odds of the building surviving future wildfires. By marketing the value of these actions, just like the remodeled kitchen or other property upgrades that attract homebuyers, you can market your asset to future insurance companies and buyers. Proactive actions, like upgrading vents, are a key part of the solution.
AB 38 (2019) started this process by mandating that the seller of a property disclose to the future buyer defensible space actions that have occurred for properties in Very High and High Fire Hazard Severity Zones. In 2025, these disclosures need to include home hardening actions based on an established low-cost retrofit list. Over time, these actions are likely going to become key for the negotiation of price and potentially the closure of the sale.
Independent assessment of preventive actions may also be helpful. The Safer From Wildfires program was established in 2023 to help promote insurance discounts for the voluntary adoption of wildfire mitigation actions; in my opinion, it could be used as an insurability assessment as well. Another option is to consider the Insurance Institute for Business and Home Safety's Wildfire Prepared Home designation. Helping your community think through the issues and take collective action to meet a Firewise designation is another approach to consider.
More information about home hardening and defensible space can be found at UC Cooperative Extension's Fire website. And if you need help navigating a recent insurance cancellation, United Policyholders, a consumer rights advocacy organization, has helpful resources.
Wildfire adaptation will not occur overnight, but I believe we have a pathway and clear evidence to demonstrate that these types of specific actions will help all of us live successfully with wildfire in California now and into the future.
- Author: Mike Hsu
Reposted from UC ANR News
Despite recent rains, fire remains a danger across California, as there's still plenty of time this fall for grass, woody debris and other flammable material to become dry and ignite.
“The smaller the fuels – pine needles, grass, and small twigs – the faster they can dry out, meaning they will be ready to burn again a few days or weeks after a large rainstorm,” said Susie Kocher, a UC Cooperative Extension forestry and natural resources advisor for the Central Sierra, urging residents to take steps to prevent or limit potential fire damage.
When it comes to “home hardening” and essential wildfire preparations in this age of drought and climate change, not every project requires a bank-breaking budget and an army of contractors.
There are small – but significant – home and landscaping improvements that most people can complete by themselves during a single weekend, with a quick run to the hardware store and some basic planning and safety precautions.
“There are a lot of factors that play into your home's vulnerability to ignition; small changes and upgrades can help reduce some of that risk for people living in high wildfire risk areas,” Kocher explained. “The bigger projects like replacing windows and roofs are very important, but there are definitely smaller projects that people can tackle right away at lower cost that also reduce risk. The main goal of these actions is to reduce the risk that wildfire embers can ignite your home.”
Kocher recommends these five measures as simple but crucial ways to bolster your home's wildfire resiliency.
Clean debris from your roof. Because of its expansive surface, the roof is the most susceptible area of your house to embers. Removing accumulated leaves and needles is especially important if you have a “complex roof” with dormers or other elements – that's where embers gather, too, and could come in contact with flammable siding. (And while you're up there, give those gutters a good swabbing.) Learn more about protecting your roof and gutters.
Install metal flashing in vulnerable spots. Replacing all your siding with noncombustible material can be pricey, but a more manageable task would be adding corrosion-resistant metal flashing to select areas: roof-to-wall intersections, the place where the chimney comes out of the roof, and the edge where the deck meets the house. Learn other ways to shore up your siding.
Remove debris from between the boards of your deck and fence. Embers can ignite leaves and needles stuck between the boards, so be sure to keep those gaps clean and clear. Learn additional steps to harden your deck and prepare your fence.
Take out all vegetation (alive or dead) within five feet of your home. Creating defensible space immediately next to your home is a top priority, so be sure there's nothing combustible within this “Zone Zero.” Plants, mulch, woodpiles, wicker furniture or anything that can catch fire should be removed. Learn what to do in the other “zones” as you move farther from your home.
Inspect vents and upgrade to finer mesh screens. Install or swap in noncombustible, corrosion-resistant metal mesh screening that is at least 1/8” (1/16” would be even better but requires more frequent maintenance). These screens help prevent embers from entering your attic and crawl space. In addition, put together some vent covers that can be deployed if you have time before a wildfire arrives. Learn other ways to reduce vulnerability of vents.
For more in-depth explanations and next steps, Kocher suggests visiting the UC ANR wildfire website (https://ucanr.edu/sites/fire/Prepare) and reviewing this home retrofit guide (https://bit.ly/3RaL54u).
- Author: Mike Hsu
Despite recent rains, fire remains a danger across California, as there's still plenty of time this fall for grass, woody debris and other flammable material to become dry and ignite.
“The smaller the fuels – pine needles, grass, and small twigs – the faster they can dry out, meaning they will be ready to burn again a few days or weeks after a large rainstorm,” said Susie Kocher, a UC Cooperative Extension forestry and natural resources advisor for the Central Sierra, urging residents to take steps to prevent or limit potential fire damage.
When it comes to “home hardening” and essential wildfire preparations in this age of drought and climate change, not every project requires a bank-breaking budget and an army of contractors.
There are small – but significant – home and landscaping improvements that most people can complete by themselves during a single weekend, with a quick run to the hardware store and some basic planning and safety precautions.
“There are a lot of factors that play into your home's vulnerability to ignition; small changes and upgrades can help reduce some of that risk for people living in high wildfire risk areas,” Kocher explained. “The bigger projects like replacing windows and roofs are very important, but there are definitely smaller projects that people can tackle right away at lower cost that also reduce risk. The main goal of these actions is to reduce the risk that wildfire embers can ignite your home.”
Kocher recommends these five measures as simple but crucial ways to bolster your home's wildfire resiliency.
Clean debris from your roof. Because of its expansive surface, the roof is the most susceptible area of your house to embers. Removing accumulated leaves and needles is especially important if you have a “complex roof” with dormers or other elements – that's where embers gather, too, and could come in contact with flammable siding. (And while you're up there, give those gutters a good swabbing.) Learn more about protecting your roof and gutters.
Install metal flashing in vulnerable spots. Replacing all your siding with noncombustible material can be pricey, but a more manageable task would be adding corrosion-resistant metal flashing to select areas: roof-to-wall intersections, the place where the chimney comes out of the roof, and the edge where the deck meets the house. Learn other ways to shore up your siding.
Remove debris from between the boards of your deck and fence. Embers can ignite leaves and needles stuck between the boards, so be sure to keep those gaps clean and clear. Learn additional steps to harden your deck and prepare your fence.
Take out all vegetation (alive or dead) within five feet of your home. Creating defensible space immediately next to your home is a top priority, so be sure there's nothing combustible within this “Zone Zero.” Plants, mulch, woodpiles, wicker furniture or anything that can catch fire should be removed. Learn what to do in the other “zones” as you move farther from your home.
Inspect vents and upgrade to finer mesh screens. Install or swap in noncombustible, corrosion-resistant metal mesh screening that is at least 1/8” (1/16” would be even better but requires more frequent maintenance). These screens help prevent embers from entering your attic and crawl space. In addition, put together some vent covers that can be deployed if you have time before a wildfire arrives. Learn other ways to reduce vulnerability of vents.
For more in-depth explanations and next steps, Kocher suggests visiting the UC ANR wildfire website (https://ucanr.edu/sites/fire/Prepare) and reviewing this home retrofit guide (https://bit.ly/3RaL54u).