- Author: Luca Carmignani
- Editor: Karey Windbiel-Rojas
- Editor: Belinda Messenger-Sikes
- Post: Gale Perez
How can weed control help with wildfire preparedness?
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.
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/
Luca Carmignani is a UC Cooperative Extension Fire Advisor located at the UC South Coast Research & Extension Center in Irvine, CA.
Original source: UC IPM Home & Garden Pest Newsletter :: Summer 2023 issue
/h2>
Advice for the Home Gardener from the
Help Desk of the UC Master Gardener Program
of Contra Costa County
Subject: Grapefruit Tree vs Woodpecker
Cllient's Request: How can we keep a woodpecker(s) from making holes in the tree bark? We don't have any insects/ants on the tree bark and we're concerned that the damage will make the tree susceptible to disease. Thank you.
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with a question about woodpeckers on your grapefruit tree. From our phone conversation this morning, I identified the culprits as sapsuckers. These drill a series of holes, usually in straight horizontal lines, in live trees so plant sap oozes out of the holes. Sapsuckers feed on the sap, as well as on any insects that become trapped in the sap. Most of the time, sapsucker holes do not cause problems for the tree. When there is continuous sapsucker activity that increases the lines of holes to a significant percentage of the tree's trunk area, it can weaken the tree and potentially kill it.
Physical exclusion is the best way to prevent any kind of woodpecker damage. There are several methods you might see mentioned to prevent such as frightening devices or repellents, but these are not typically successful as birds quickly become accustomed to the deterrent. Covering the trunk with something that will prevent access to the tree bark is the best way to get sapsuckers to move on. Sections of lightweight sheet metal or roof flashing are fairly easy to shape around the trunk. You can get rolls of aluminum flashing at home improvement stores. Heavyweight plastic material can also be used. Use duct tape to hold it in place. You can also use wire mesh such as chicken wire, especially if it's bunched up somewhat. You will probably need to cover a great deal of the tree's bark to prevent the birds from just moving to an uncovered area. Whatever you use to cover the bark, make sure it is not too tight--you want to leave room for the tree to grow--and remove it when the birds have moved on. Depending on the size of the tree, you could also cover the entire tree with bird netting that you securely attach around the low base of the trunk to prevent all access to the tree.
Woodpeckers drill holes in trees for a variety of reasons. The largest holes are drilled for nest construction, usually in dead trees. Acorn woodpeckers drill 1/2 inch holes in which they store acorns. Smaller random holes are those made while looking for food. Woodpeckers' sharply pointed beaks and long tongues are used for extracting larvae and other insects from wood crevices. This can actually alert you to burrowing insects damaging a tree.
This link is to more information from the University of California about managing woodpeckers: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74124.html.
I hope this information is helpful. Please don't hesitate to contact us again if you have more questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
- Author: Janet Hartin
The University of California Cooperative Extension San Bernardino County Master Gardener program is now accepting applications for the October 1, 2019 - February 18, 2020 Master Gardener class on Tuesday evenings in Redlands. (There are no classes on Dec. 25 and Dec. 31.)
The class provides 50 hours of training on sustainable landscaping and growing food in home, backyard, and community gardens and is taught by University of California experts and knowledgeable practitioners. Master Gardeners come from all walks of life and no college degree is required. What successful applicants have in common is a passion for sharing knowledge gained from the training class with residents of San Bernardino County. Accepted applicants agree to volunteer a minimum of 50 hours by June 30, 2021 via one or more outreach methods: answering email and phone helpline questions; making presentations at workshops and community events; staffing information booths at Farmers Markets and other non-profit events; writing blogs and promoting the program via social media; working with communities and schools to develop gardens; and working with Healthy Communities throughout San Bernardino County to encourage outdoor exercise and activities. Accepted applicants must pass two open-book exams, present a group class project, and pass a background check (approximately $30). The class fee (includes training materials) is $175. Visit our UCCE Master Gardener website for more information and to complete an online application: UCCE San Bernardino County Master Gardener Website. Applications must be received through the online system by or on August 31, 2019 to be considered.
There is a hybrid partially online option for residents of the high desert and mountains. Simply select this option on the application if this pertains to you. All costs and requirements remain the same as for in-class students.
Questions? Contact UCCE Master Gardener Coordinator Maggie O'Neill at magoneill@ucanr.edu
We hope to hear from you!
MG SB Application 2020 Redlands
- Author: Cris L. Johnson
The Master Gardeners of Ventura County will host one of their seasonal home-garden workshops in August. This workshop will focus on "Growing Enviable Orchids and Roses," and will include a continental breakfast, snacks and a docent-guided tour of the Faulkner home.
Gardening experts will guide orchid and rose enthusiasts with techniques to turn their blooms into showcase beauties.
The Master Gardeners love to share their expertise and love of gardening. Workshops are held on Saturdays so more members of the public can participate.
Date: Saturday, August 16, 2014
Time: 8:00 am - 12:00 noon
Location:
Hansen Agricultural Research and Extension Center
14292 W. Telegraph Rd.
Santa Paula, CA
Fees:
General Public - $20
Master Gardeners - $10
For more information see this flyer; link here to register.
- Author: Cris L. Johnson
Join the UC Ventura County Cooperative Extension's Master Gardeners at their summer workshop, "All About Roses, Plant Propagation."
Our hard-working Master Gardeners present a workshop for each season of the year and this one is devoted to sharing information about pruning, watering and fertilizing roses and dealing with any pesky pests.
Time: 8:15 am - 12:00 pm
Location:
Hansen Agricultural Center
14292 W. Telegraph Rd.
Santa Paula, CA
(Use Briggs Rd. Entrance)
The Master Gardeners love to share their expertise and love of gardening. Workshops are held on Saturdays so more members of the public can participate.
Cost: $30 (includes continental breakfast and snacks)
To view the flyer, please click here; or to online register.