- Author: Michael I Jones
From an entomologist's perspective, 2023 couldn't have been a more interesting year for oak pests!
But, what causes the wounds that introduce the bacteria to the acorns? Well, it can be many different things, including physical damage or things that feed on acorns. Perhaps the coolest of the things that eat acorns are the insects that rely on the acorn for their food and reproduction, acorn weevils (filbert weevil) and filbertworms.
The timing of these acorn drops makes it seem like the oaks are "using" fire to help control the pests of the seeds. Well, they are... in a sense. Oaks have co-existed with fire (both from lightning and Native Californians using fire as a tool) for thousands of years so holding on to healthy acorns until after fire season is one more fire-adapted strategy exhibited by the oaks.
While I was following acorn pests throughout the year, in early December I started to receive questions about coast live oak with leaf discoloration and loss in Sonoma County.
- Author: Brent McGhie, UC Master Gardener of Butte County
No doubt you have seen many species of oaks living in wild areas of Northern California. But native oaks can also be attractive and beneficial additions to the home landscape.
The key to living with oaks is to disturb them as little as possible. This is especially true of the root crown (the base of the trunk) and the root zone. The root zone of an oak tree covers an area one-third again larger than the outermost edge of the tree's foliage. Strive to keep this area as natural as possible.
The fungal disease “oak root rot” (Armillaria mellea) has evolved with California oaks. It is parasitic on oaks and other plant species, but if oaks are growing naturally in our moist winter/dry summer environment, this fungus is kept in check. However, if oaks are provided with summer irrigation in their root zone, Armillaria can become an aggressive, deadly pathogen. Do not water any plants under oaks during the summer: if they need watering, they do not belong there. Instead, native plants that are adapted to our Mediterranean climate can be grown under oaks. If winter rains are unusually low, a supplemental watering can be provided in the early spring. Do this by watering deeply in the outer two-thirds of the root zone.
Other threats to the root zone include soil compaction, paving, trenching, and changes in grade or drainage. If soil is mounded under an oak, the oxygen supply to the roots can be reduced, which can suffocate the tree. Oxygen exchange with the roots may also be reduced if the soil is compacted or covered with paving. Suffocation can also occur when drainage patterns are altered and the soil around an oak becomes saturated for extended periods. Excavating by grading or trenching can cut or damage roots. When enough roots are damaged, trees will die.
Learn more about the many benefits native oaks provide to our local ecosystem: Attend our workshop, “Plant an Acorn; Harvest a Community” on Tuesday, November 7th. For descriptions of this and all the other workshops in the Master Gardeners' Fall Workshop Series, visit our website. All workshops are free, but registration is required.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
- Author: Pamela Kan-Rice
The 8th California Oak Symposium will be held Oct. 31–Nov. 3 in San Luis Obispo, and anyone involved in research, education, management or conservation of California's oak woodlands is invited to participate.
The theme of the symposium is “Sustaining California Oak Woodlands Under Current and Future Conditions.” The four-day event's 62 concurrent session talks and 30 posters will cover climate change, wildlife ecology, oak restoration, oak pests and diseases, fire ecology, and ranch management and generational transfer.
Oak scientists, foresters, tribal members, land managers, policymakers and other interested individuals will gather to discuss the state of knowledge about the science, policy and management of California's oak woodlands.
“Given the risks associated with climate change, conservation of this diverse ecosystem is an especially critical management and policy priority today,” said symposium co-chair Bill Tietje, University of California Cooperative Extension natural resources specialist based in San Luis Obispo.
The symposium will kick off on Oct. 31 with three optional tours to observe Central Coast oak management and conservation. The Dangermond Preserve tour will provide a glimpse into the home of 54 special status species – including 14 threatened and endangered plant and animal species – in 6,000 acres of coast live oak woodlands at Point Conception. On the Sinton Family Avenales Ranch tour, Steve Sinton, co-founder of the California Rangeland Trust, will discuss the history and management of the ranch, which offers hunting and hosts UC Cooperative Extension long-term research projects. The Oak Conservation tour will visit the Cuesta Ridge oak diversity hotspot, Learning Among the Oaks outdoor education and youth environmental leadership training program, Santa Margarita Vineyard and oak restoration activities at Cayuse Ranch.
Keynote speaker David Ackerly, dean and professor of UC Berkeley Rausser College of Natural Resources, will open the second day with an overview of climate change and oaks. Other speakers will discuss the science of climate change, management of oak woodland under changing environmental conditions, and the maintenance of working landscapes and the essential services they provide to society.
On the third day, two special-topic panels will describe California oak programs for schools, citizen scientists and underrepresented groups. Panelists will also describe technologies used to increase understanding of the oak woodland ecosystem and how to apply the information.
The closing day will feature a plenary session on managing and maintaining working landscapes during prolonged drought. To wrap up the symposium, Paul Starrs, University of Nevada-Reno emeritus professor, will deliver the capstone talk, “Where Have We Been and Where Are We Going?”
Beginning in 1979, seven symposia have been held every five to seven years to address the state of knowledge about the science, policy and management of California's oak woodlands. The eighth in the series was originally set for 2020, but postponed due to the pandemic.
For more information, including the full program, and to register, visit https://ucanr.edu/sites/oaksymposium.
- Author: Denise Godbout-Avant
Plants
If you have the space, plant an oak tree! While it will take several years for the tree to mature, few plants provide more benefits to nature than an oak tree. One Valley oak tree can provide food, water, and shelter to approximately 350 vertebrate species and over 250 species of insects and arachnids.
Choose plants that bloom at different times of the year, to ensure something is always blooming during the different seasons thus providing nectar sources year-round. Include some plants which produce berries to provide food sources attractive to birds and insects.
Lawns lack variety, thus reducing your lawn space and replacing it with native plants will increase the diversity in your garden. Decreasing the frequency of mowing permits grasses to grow taller, allowing flowers to grow and bloom which would attract bees and butterflies. You can also sprinkle some daisy and clover seeds into your lawn to provide forage plants and flowers for many beneficial insects.
Water
Ponds with aquatic-loving plants can encourage amphibians such as salamanders or toads, or wetland insects such as dragonflies, to visit and set up their homes.
Butterflies engage in behavior called “puddling,” where they stop in muddy puddles for water and nutrients. You can recreate this by filling a terra cotta saucer with soil and pebbles, sink it into the ground and keep it moist. Again, change the water regularly.
Plants and rocks around the water source(s) provide shelter, camouflage, and spots for creatures like butterflies, lizards, or turtles who like to sun themselves near water.
Housing for Bees
Leave the Leaves
Leaving leaves as they drop from your trees and bushes provides food and shelter for a variety of living creatures including worms, beetles, millipedes, larvae of some butterflies and moths, toads, frogs and more. These in turn attract birds, mammals, and amphibians that rely on the smaller organisms as a food source.
Chemicals
One Step at a Time
Changing your garden into a wildlife haven will likely be a step-by-step process over a period of time. Building a garden attractive to wildlife will bring you the enjoyment of watching them and the knowledge you are helping wildlife thrive.
Resources listed provide information for ways to you to build a garden attractive to wildlife.
- Butterflies in Your Garden: https://ucanr.edu/sites/CEStanislausCo/files/345791.pdf
- Sustainable Landscaping: https://ucanr.edu/sites/stancountymg/Sustainable_Landscaping/
- Trees in Your Garden: https://ucanr.edu/sites/CEStanislausCo/files/341553.pdf
- Pollinator-Friendly Native Plants Lists: https://xerces.org/pollinator-conservation/pollinator-friendly-plant-lists
- UC IPM Statewide Integrated Pest Management Program: http://ipm.ucanr.edu/
- The Bee Gardener: The Cavities You Want to Have: https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=12785
- How to Make and Use Bee Houses for Cavity Nesting Bees: https://beegarden.ucdavis.edu/wp-content/uploads/2018/04/How-to-build-and-use-bee-blocks.pdf
Denise Godbout-Avant has been a Stanislaus County Master Gardener since 2020.
/h3>/h3>/h3>/h3>/h3>/h3>- Author: Pamela Kan-Rice
Academics, agency personnel, land managers and ranchers are encouraged to submit presentation and poster abstracts for the 8th California Oak Symposium, which will be held March 21-24, 2022, in San Luis Obispo.
The theme of the symposium is “Sustaining Oak Woodlands Under Current and Future Conditions.” Abstracts should be submitted at https://ucanr.edu/sites/oaksymposium/Call_for_Abstracts/Call_for_Abstracts and are due by 12 noon on Aug. 16, 2021.
- Ecology and Wildlife
- Climate Change
- Fire
- Land Use and Conservation
- Pests and Diseases
- Policy
- Practical Applications for Management
- Urban Oaks
- & much more!
Please review the call for abstracts details and information for speakers on the website.
David Ackerly, dean of the UC Berkeley College of Natural Resources, will deliver the climate change session keynote “Setting the Tone: An Overview of Climate Change and Oaks.” Visit the online agenda to view the all confirmed sessions and speakers to date.
For more information about the program, visit https://ucanr.edu/sites/oaksymposium or contact Bill Tietje, co-chair. For logistics information, contact UC ANR Program Support, Julia Kalika or Sherry Cooper at (530) 750-1361