- Author: Humboldt Del Norte Counties Help Desk Team
Q: I have lots of weeds in my orchard. I've tried hand pulling and a high concentration of vinegar without much success to get rid of the stinging nettle, horsetail, hemlock, and wild radishes. Can I use herbicides?
A: So, what is a weed? It is a plant that is out of place, unwanted, or interferes with crop or livestock production. Weeds can also protect and restore exposed soils, provide habitat for beneficial organisms, such as pollinators, make nutritious food and fodder, and replenish and restore soil life.
Weed management includes hand pulling, mowing, decreasing the seed bank, and allowing them to grow in a controlled manner. Using herbicides is another tool in the toolbox and are effective when applied with knowledge and safety. Here are some resources for you about the identified weeds and the use of herbicides/pesticides. We encourage you to follow all directions and precautions when using chemicals so that you do not harm yourself or the environment.
Resources:
Weeds – Identifying and Controlling https://ucanr.edu/sites/hdnmastergardeners/Resources_for_Home_Gardeners/Weeds_-_Indifying_and_Controlling/
Weed Control in the Vegetable Garden
https://yardandgarden.extension.iastate.edu/how-to/weed-control-vegetable-garden#herbicides
How to Manage Pests in Gardens and Landscapes, Burning & Stinging Nettles https://ipm.ucanr.edu/PMG/PESTNOTES/pn74146.html
Common Horsetail, U.S. Forest Service https://www.fs.usda.gov/wildflowers/plant-of-the-week/equisetum_arvense.shtml#:~:text=Equisetum%20arvense%20range%20map.,Common%20Horsetail%20(Equisetum%20arvense)
It's True What They Say About Horsetails, Patricia Matteson, December 20, 2022 https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55810
Horsetails Weed Report from the book Weed Control in Natural Areas in the Western United States
https://wric.ucdavis.edu/information/natural%20areas/wr_E/Equisetum.pdf
How to Manage Pests in Gardens and Landscapes, Poison Hemlock
https://ipm.ucanr.edu/PMG/PESTNOTES/pn74162.html
UC IPM Pesticide Information, Active Ingredient: 2, 4-D
https://ipm.ucanr.edu/TOOLS/PNAI/pnaishow.php?id=3
Warning in the Use of Pesticides, https://ipm.ucanr.edu/PMG/PESTNOTES/warning.html
UC IPM Weed Gallery – Wild Radish https://ipm.ucanr.edu/PMG/WEEDS/wild_radish.html
- Author: Birgitte Elbeck, UCCE Master Gardener
If your garden is on the coast, you might easily choose to bypass this article.
Please read the closing paragraph on Coastal wildfire concerns before moving on to another topic, you may find it useful.
Introduction:
To the extent that the Humboldt and Del Norte Master Gardeners have a slogan, it is ‘Right Plant Right Place.' Four little words to encompass all the considerations for predicting whether a plant will do well in a specific spot in your garden. Typically, these considerations center around your particular location's climate and microclimate, soil, water, amount of sun, and the maintenance that you will be able to give the plant. These considerations are fundamental for creating a healthy and enjoyable garden. However, with the advent of increased wildfire activity in California and around the world, additional constraints are needed in your garden landscape in order to increase the odds that your home will remain safe from wildfire. Satisfying all the constraints in a single season may feel too overwhelming, so you may want to initially pick some items to fix that you feel will make your specific situation safer. Home hardening efforts should always be considered alongside the Fire-wise enhancements to your garden, but this article will not cover those aspects.
Basic principles for creating a Fire-wise & sustainable landscape:
- Adhere to the evolving Defensible Space guidelines.
- Keep your garden's unique aspects in mind.
- Select all plants carefully and place them in locations that will give them adequate room to grow.
- Design for ease of maintenance.
- Communicate and cooperate with your neighbors.
- Do what is required by law. Scientific research on the new reality of wildfire is ongoing; use science to inform your decisions.
Defensible Space and placement of plants:
The premise for fire-wise landscaping is quite simple: change the garden and landscape around the home in order to protect the structure. However, the implementation can sometimes be tricky, often involving cooperation with neighbors, and it always requires maintenance and vigilance over time to remain effective. Talking to neighbors and coordinating within the immediate neighborhood should be an essential part of your efforts. Remember, by working together, you can create a safer environment for everyone in your community.
The concept of ‘defensible space' is a cornerstone of fire-wise landscaping, as promoted by CalFire and other fire-related agencies. It involves managing zones of varying levels of fuel reduction, with the most stringent reduction near the home, and considering the relative placement of landscape components. This approach outlines prudent spatial landscaping constraints, particularly in rural settings with ample space and trees. Its primary focus is on halting the path of fire toward your house and ensuring the safety of firefighters operating in your vicinity during a fire. In your garden design, it is advisable to think in terms of ‘islands' of plantings rather than continuous hedges or other plantings.
There are three zones to take into consideration.
- Zone 0 is the first 5 feet out from the house, focusing on intense fuel reduction to protect against ember attacks. Zone 0 is a recent addition, and you may still find websites, etc., that do not reference it. It was implemented after it became clear that an exceptionally large percentage of structure fires start from flying embers that get caught immediately next to a building. Such flying embers can come from a blaze that is a mile or more away, making it difficult to predict when and where embers will land.
- Zone 1 covers from 5 feet to 30 feet. The goal is to reduce fuel sources and includes removing all dead plants, leaves, and grass, pruning overhanging branches and flammable plants and shrubs near windows, allowing 10 feet between trees,
- Zone 2 from 30 feet to 100 feet. The goal of Zone 2 is to reduce fuel sources.
The illustration below shows the bands of zones. The defensible space rules are still evolving, and your best bet is to get updated information at Defensible Space | CAL FIRE.
For more information about defensible space https://readyforwildfire.org/prepare-for-wildfire/defensible-space/
Plant spacing of grasses, shrubs, and trees is key in slowing the spread of wildfires. Spacing varies depending on the slope of the land, plant and tree type, and size.
Wildfires travel at different speeds based on many factors, but it is generally true that fire moves up-slope at a fast pace. If your home has a slope down from it, then you will need to pay attention to the spacing of trees and other plants. The steeper the slope, the more generous the spacing needs to be. Note in the sketches below that if there are bushy ‘ladder fuels' under the trees, then the distance is not from one tree trunk to another, but instead from one ‘island' to another.
SLOPE & DISTANCE Between Plantings
Vertical spacing
- Trim branches at least 6 feet from the ground.
- Increase vertical space between shrubs and trees to prevent the fire from climbing. For example, a 5-foot shrub near a tree will need 15 feet of clearance to the tree's lowest limbs.
Horizontal spacing
- Is determined by the slope of the land.
- The steeper the slope, the greater the distance between plants/trees. See the illustration on the right.
Plant placement and maintenance are more important than plant attributes, and plant attributes are more important than specific plant species:
As you have seen, Defensible Space is focused on spatial considerations. The specific plants for your Fire-wise garden should be chosen based on their physical characteristics and on the amount of care that you plan to give them. Keeping up with irrigation, pruning, and leaf litter cleanup is essential, even with plants that are less fire prone. All plants can burn, regardless of how they are marketed!
Plant attributes: |
Comments: |
Does the plant contain a lot of waxes, oils, and resins? |
A plant with more waxes, oils, and resins will likely be more flammable and release more energy when it burns. (Conifers are generally high in resins.) |
What is the leaf moisture content? |
Leaves with higher moisture content are less flammable than drier leaves. (See more on succulents below.) |
Does the plant have an open-growth structure? |
A densely structured plant can capture embers and may be more likely to ignite. It will also be more likely to be easily ignited by a surface fire. (See the Crape Myrtle example below.) |
How fast does the plant grow? How tall will the plant grow? |
A plant that grows quickly may exceed growth expectations and require greater maintenance. Pruning, maintenance, and cleanup can have a greater impact on whether a plant ignites than does the type of plant it is. |
Does the plant shed bark, leaves, or needles?
|
A plant that sheds bark or branches is likely to need more regular maintenance-related cleanup to reduce fuel accumulations on the ground. (Example: Eucalypts) A plant that has a big leaf or needle drop will result in the need for more maintenance-related cleanup on the property, on the roof, and in rain gutters. |
Is the plant native to the area? |
Native plants, pollinator-friendly, or drought-tolerant plants can be good choices for those labeled qualities, but these features do not directly translate to fire resistance. |
Fire resistant plants.
Labeling any plant as fire-resistant is an oversimplification of a complex problem. There can also be confusion as to whether a plant is resistant (does not easily catch fire) or resilient (has the ability to survive or has seeds that will survive). So, relying on lists of fire-safe plants is not the best thing to do. Below are just a couple of examples of plants that you may find on such lists, with some corresponding comments.
Crape myrtle (Lagerstromia indica)
These beautiful small trees (or bushes) tend to develop suckers that, if not removed, can form a dense cluster. The crowns can become dense, so they require ongoing pruning and thinning. Also, some gardeners like them positioned as hedges, which could cause a fire to travel quickly along the length of the hedge.
Manzanita (Arctostaphylos spp)
These native plants range from low, spreading plants to large bushes. They have a lot of appeal both because of their flowers and their striking bark. In a garden they are sometimes planted under larger trees, thereby creating a ‘ladder' for a fire to reach the crown of a tree above it. If a manzanita burns, it burns hot, but in the wild they have an amazing ability to re-sprout from the root, making them resilient.
Succulents (numerous genera)
In zone 0, succulents may be a choice for those of us who are not excited about switching to hardscape around the house. There are many varieties of succulents that hug the ground and contain a lot of water in their fleshy leaves. It has been suggested, though the jury is still out on this, that such plants, when well maintained, may actually help keep swirling embers from reaching the base of your house. Sonoma County's Master Gardeners have a great page on succulents: https://sonomamg.ucanr.edu/Recommended_Plants_for_Sonoma_County/Succulents
Coastal wildfire concerns:
The counties of Humboldt and Del Norte are blessed with a long, beautiful coastline with a cool and moist climate, and most of our population lives near the ocean. It is the hotter, forested inland areas that have seen the bulk of the wildfires. However, the coastal communities should not be complacent, as indicated by this snippet (Chapter 14 Wildfire Hum Co-LHMP (ca.gov)):
Despite the generally damp climate prevailing in these forests, studies have suggested a historical fire return interval of 50 to 100 years in the northern part of [Humboldt County] and 12 to 50 years in the south. Several of the more destructive historical fires occurred on the coast around the Trinidad area, including the 7,432-acre Luffenholz Fire of 1908, the 17,527-acre A-Line Fire of 1936, and a 15,000-acre unnamed fire near Patrick's Point in 1945.
Resources:
Much of this article is based on a document from Humboldt/Del Norte's own Yana Valachovic, Forest Advisor for the University of California Cooperative Extension and Humboldt – Del Norte County Advisor and colleagues: Reducing the Vulnerability of Buildings to Wildfire: Vegetation and Landscaping Guidance _UC ANR publication 8695.
CalFire
Defensible Space https://www.fire.ca.gov/dspace and https://readyforwildfire.org/prepare-for-wildfire/defensible-space/
- Author: Lisa Nedlan
I can name that flying insect in 3 clues – how about you?
Match the clue to the insect's image. Place an X in the appropriate column.
Resources:
UC IPM, Syrphids (Flower Flies or Hover Flies) https://ipm.ucanr.edu/natural-enemies/syrphids/
University of Florida, European honey bee https://entnemdept.ufl.edu/creatures/misc/BEES/euro_honey_bee.htm
University of Minnesota Extension, Syrphid flies https://extension.umn.edu/beneficial-insects/syrphid-flies
US Forest Service, Syrphid fly (Sphaerophoria philanthus) https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/syrphid-fly.shtml
Utah State University Extension, Beneficial Predators: Syrphid Flies https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2969&context=extension_curall
Photo credits:
Honeybee photo by Leo Kriss: https://www.pexels.com/photo/macro-photography-of-honeybee-perched-on-blue-petaled-flower-754313/
Syrphid Fly photo by Leslie Saunders on Unsplash
- Author: Tim Walsh, UCCE Master Gardener
- Author: June Walsh, UCCE Master Gardener
Why, what's the matter,
That you have such a February face,
So full of frost, of storm and cloudiness?
–William Shakespeare, from "Much Ado About Nothing"
Back in 2008, when we first began to garden, plan, and plant the Moss Family Temperate Woodland Garden in Humboldt Botanical Garden, we had a bare canvas and mostly bare earth except for the amazing load of weed seeds from the native soil and the many loads of trucked-in horse-barn shavings, spoiled feed, and manure.
We learned quickly that water flows downhill and over our beautifully compacted and rocked pathways and stairs. As the water flowed, it carried soil, eroded our new paths, and sought and took its own path. We learned where the water would run all year and where it would only run until the first of summer, and we learned to take advantage of its special qualities and behaviors.
Tim and I had been to Pukeiti Garden in New Zealand (https://www.trc.govt.nz/gardens/pukeiti/), where the prodigious rain (4 meters or 160 inches) caused the gardeners to dig 3-foot-deep and wide ‘gutters' along their pathways. They also had large culverts where the pathways crossed the rain flow. We and our volunteers learned to use trenching tools to cut gutters along our pathways to give the water a place to run without too much destruction.
When considering how to manage water runoff, think about slowing down the flow of the water, creating low-lying areas in the garden to provide short-term storage for heavy runoff, and allowing sediment and water to soak into the ground instead of entering storm drains and creeks. Also, consider planting plants with fibrous root systems along the edges to prevent runoff and soil erosion. For more information, visit https://ccuh.ucdavis.edu/sites/g/files/dgvnsk1376/files/inline-files/landdesign%20water%20quality%20english.pdf
This time of year, keeping our 16-year-old gutters free of debris is a major task for our volunteers and staff. Luckily, our deciduous trees are finished with their fall disrobement and the leaves have been removed from gutters and pathways by the Wild Weeders and Grateful Deadheaders. The leaves are repurposed into the garden beds.
During our Docent-led tour on Saturday, February 3rd, we saw the blooming Camellia reticulata along the road and the first of our brilliant pink Magnolia sprengeri var. diva 'Diva' and Magnolia ‘Caerhay's Belle' (M. sargentiana var. robusta × M. sprengeri ‘Diva'. These plants give the garden dramatic pops of color on otherwise dreary days. Tim says, “The joy of these magnolias is that they bloom in February, and the sorrow is that they bloom in February as wind and rain can strip the flowers.”
Soon the Wild Weeders and Grateful Deadheaders will begin their annual Camellia purgatory of spent blossom cleanup. We pick up the spent flowers to help prevent Camellia petal blight which is a disease caused by the fungus Ciborinia camelliae. Though our C. reticulatas are less susceptible than C. japonica or the Williams hybrids, we want to do what we can to prevent our flowers from turning brown and falling off prematurely.
Come visit the temperate woodland garden at Humboldt Botanical Garden to see how we manage water run-off, maintain the plants and soil, enjoy the lovely blossoms, and see how the garden changes throughout the seasons.
Resources:
Landscape Design & Water Quality
https://ccuh.ucdavis.edu/sites/g/files/dgvnsk1376/files/inline-files/landdesign%20water%20quality%20english.pdf
Landscape Plants: Fertilizing & Watering
https://ccuh.ucdavis.edu/sites/g/files/dgvnsk1376/files/inline-files/landplants%20fertilizing%20watering%20english.pdf
Soak Up the Rain: Rain Gardens
https://www.epa.gov/soakuptherain/soak-rain-rain-gardens
- Author: Birgitte Elbeck, UCCE Master Gardener
- Author: Jody Greaney, UCCE Master Gardener
Many of us enjoy birds, but we may be inadvertently hanging “No vacancy” signs over our gardens. Research by entomologist Doug Tallamy shows that to raise their young, birds need caterpillars – lots of them. Songbirds as little as chickadees require some six to nine thousand caterpillars to raise a brood of nestlings. In fact, ninety-six percent of terrestrial songbirds rely on caterpillars to feed their babies. The prevalence of these small, soft-bodied, protein-rich larvae affects where the birds choose to nest and how big a territory they need to defend.
Fortunately, we have a good jump on knowing what these vital keystone species are. The information presented below, and the identification of keystone plant genera is based on the research of Doug Tallamy of the University of Delaware, author of Nature's Best Hope.
Here is a list of resources/databases to help you select keystone plants to support caterpillars and birds in our area:
- Calscape - Restore Nature One Garden at a Time. Enter the city where you live to see a list of native plants to choose from. You will find lots of information about each plant: images, descriptions, growth habits, and the number and types of butterflies and moths supported to name a few. (The numbers of moths and butterflies hosted indicated in the plant list below are from this search tool.)
- Audubon - Native Plants, Bring more birds to your home with native plants. Enter your zip code to see plants suited to your area and the birds they will support.
- National Wildlife Federation, Native Plant Finder Select from a list of host plants for butterflies and moths. Plants are ranked by the number of caterpillars hosted.
Using the databases above, we have put together a list of native plants that do well in our area and support butterflies and moths, which provide caterpillars to feed the birds. They all support numerous caterpillar species in our area. Numbers in parentheses indicate the probable number of caterpillar species supported.
Shrubs: Willows (211), Bitter Cherry (156), Ceanothus (85), Currants and gooseberries (85), Huckleberries (65), Wild Roses (66), Lupines (55), Manzanitas (56)
Perennials: Thimbleberry (70), Cow's Clover (67), Goldenrods (53), Beach Strawberry (32), Coast Buckwheat (31)
Annuals: Native Clovers (70), Miniature Lupine (54)
For more detailed information on these and other native plant species options for your growing conditions, visit Calscape - Restore Nature One Garden at a Time
If you would like to visit a local native garden, the North Coast CNPS, California Native Plant Society, has an extensive list of local native gardens from Trinidad to Ferndale.
Protecting The Birds That Visit Your Garden
OK! You've planted your keystone species, the caterpillars are on their way, and our feathered friends will follow. Yay!! But not surprisingly, the birds, like us, need more than just food. Here are a few steps to help you turn your avian restaurant into a home.
Reduce or eliminate pesticide use: Integrated Pest Management (IPM) strategies, such as proper plant selection, can help gardeners adopt more sustainable landscape practices.
Provide Fresh Water: Place a birdbath in the landscape and be sure to keep it clean. If you are really ambitious, a small fountain with protective plants around it will attract the birds!
Add a nest box (birdhouse) - Nest boxes can provide valuable homes for many birds For more information about nest box design and placement for specific birds visit https://nestwatch.org/learn/all-about-birdhouses/.
Keep cats indoors: Free-roaming cats kill 2-3 billion birds yearly. If you want your cat to experience the outdoors, please consider building an enclosed cat patio (catio.)
Prevent window strikes: Up to a billion birds are killed every year from collisions with windows. The site below has ideas on how to prevent these accidents.
Layer your yard's habitat:
- If you have space, consider adding large shrubs or small trees such as Bitter cherry (156), Toyon (4), Coffeeberry (23), Cascara Sagrada (27), Red Alder (70), or Vine Maple (55). These trees/shrubs not only support caterpillars but can also provide fruit and nuts, nest cavities, and perches.
- Smaller shrubs, in addition to perennials and annuals, can provide cover and seeds for birds.
- Leave some decayed leaves, twigs, and other plant debris on the ground to provide homes for invertebrates that birds eat, including the pupae of most moth caterpillars.
Leave the seeds: Do not deadhead seedheads; they can be an important food source during fall and winter. Consider planting native plants such as Woolly Sunflower (Eriophyllum lanatum), California Aster (Corethrogyne filaginifolia), and Deergrass (Muhlenbergia rigens). These plants produce a profusion of seeds that attract and support seedeaters, such as finches and sparrows.
Especially for hummingbirds:In addition to soft-bodied insects and larvae, hummingbirds can feed on nectar from most any flowering shrub, tree, vine, perennial, or annual. They are especially attracted to native species with orange, pink, and red tubular flowers, such as Humboldt County Fuchsia (Epilobium septentrionale) and Hummingbird Sage (Salvia spathacea). Manzanitas, gooseberries, and currants are important for caterpillars and can also supply nectar in the colder months.
So, what are you waiting for? Now that spring planting is near, it is time to flip that “No Vacancy” sign to “Birds are Welcome!”
For more information related to protecting birds visit:
University of California, Sustainable Landscaping in California https://anrcatalog.ucanr.edu/pdf/8504.pdf
Audubon, How to Clean a Birdbath — Attracting Birds to Your Yard | Audubon https://www.audubon.org/news/why-you-should-keep-your-birdbath-clean
NestWatch, All About Birdhouses https://nestwatch.org/learn/all-about-birdhouses/
American Bird Conservancy, Cats and Birds https://abcbirds.org/program/cats-indoors/cats-and-birds/
American Bird Conservancy, Solutions for Pet Cats, Catios and Outdoor Enclosures https://abcbirds.org/catio-solutions-cats/
Cornell Lab, All About the Birds, Why Birds Hit Windows – And How You Can Help Prevent It https://www.allaboutbirds.org/news/why-birds-hit-windows-and-how-you-can-help-prevent-it/#