- (Focus Area) Yard & Garden
- Author: Kathy Keatley Garvey
In the sweltering heat of Solano County (100 degrees) during National Pollinator Month, how about an image of a sweat bee, genus Halictus, a tiny bee that's often overlooked in the world of pollinators.
It's a social bee that nests in the soil. "These nests consist of a complex of tunnels with individual brood chambers," according to California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday), the work of UC-affiliated scientists,
My camera caught this Halictus flying over Coreopsis in our Vacaville pollinator garden on June 5.
Camera: Nikon Z8 with a 50mm lens
Settings: Shutter speed, 1/4000 of a second; f-stop, 5; ISO 500.
UC Davis distinguished professor emerita Lynn Kimsey, emeritus director of the Bohart Museum of Entomology, and Bohart Museum scientist Sandy Shanks said the species appears to be Halictus ligatus.
Most Halictus species are generalist foragers, according to the Great Sunflower Project. "They use all sorts of genera of plants from the Asteraceae to Scrophulariaceae. They are very common on composites (daisy-like disc and ray flowers) in summer and fall."
We've seen them on everything from mustard to milkweeds to catmint to rock purslane, from spring to fall. They also appear regularly on the tower of jewels (Echium wildpretii).
Not to mention the Coreopsis.
/span>- Author: Lauren Fordyce
Pampasgrass (Cortaderia selloana) is a common ornamental landscape plant that readily naturalizes throughout California's coastal areas and some interior regions. Historically, pampasgrass was planted for erosion control, but it has since escaped cultivation and spread along sandy, moist ditch banks throughout coastal regions of southern California. Pampagrass can also grow in the hot, dry climate of inland areas of California.
A similar-looking invasive grass, jubatagrass (Cortaderia jubata), is more widespread, aggressive, and is a major pest in coastal redwood forest areas. Jubatagrass thrives in cool, foggy environments and does not tolerate temperature extremes or drought.
Both pampasgrass and jubatagrass outcompete native plants; a single floral plume can make 100,000 seeds in a year. They create fire hazards with excessive build-up of dry leaves, leaf bases, and flowering stalks. In addition, their tough leaves have serrated edges that can easily cut skin.
What can you do?
Choose non-invasive ornamental grasses to plant in your garden or landscape. Many species, including native grasses, can resemble pampasgrass or jubatagrass. This includes several species of Muhlenbergia: deer grass, white awn muhly, and Lindheimer's muhly. California native Pacific reedgrass grows well on the coast and is deer resistant. For a large, tough bunchgrass, try giant sacaton, a native of the Southwest. Giant wildrye, another California native, will grow into dense stands that attract birds.
To learn more about these invasive species and alternatives to plant, visit https://plantright.org/invasive/cortaderia-selloana/ or https://plantright.org/invasive/cortaderia-jubata/.
For more information on their management, visit https://wric.ucdavis.edu/information/natural%20areas/wr_c/cortaderia_jubata-selloana.pdf.
Why are wine bottles tall and narrow? That distinctive shape contributes to the happy marriage between cork and a bottle made tall enough to lie on its side so the wine can “breathe” through the cork as it matures. Lying on its side while stored in cool, dry cellars ensures that the liquid within the bottle will marinate the cork end just enough to keep it from drying out and crumbling.
What do wine, wax, and wrinkles have to do with local trees? In 1904, a cork oak grove was planted in Lower Bidwell Park near the Nature Center on East 8th Street. The grove was located within a 29-acre tract of land that John Bidwell donated in 1888 to the newly created State Board of Forestry for use as a woody plant nursery and demonstration plantation.
Cuttings and young plants were collected from all over the globe for the project, including species of willow, mulberry, linden, maple, oak, catalpa, pine, and eucalyptus. The ensuing planting spree in the 1890s included Sequoia gigantica, a tract of Italian cypress (these trees gave rise to the name “Cedar” Grove), and a large plot of Scots pine. Of those late-19th century conifer plantings, only the cypress remain: the Sequoia were decimated by a freak freeze in 1932, and bark beetles took all but a few of the pines.
The species can reach about 66 feet in height, but is usually smaller than that in its native habitat. There are two notable exceptions: In Portugal, the Sobreiro Monumental (Monumental Cork Oak), is 234 years old and 52 feet tall, with a trunk so large in circumference that it takes up to five people with outstretched arms to encircle it. It is listed as a National Monument, and cited in the Guinness Book of Records as the largest and oldest cork oak in the world. Closer to home, a Quercus suber in Napa is registered as a California Big Tree. It is 89 feet tall, with a trunk circumference of 20 feet, and a crown spread of 81 feet.
The acorns of the cork oak have a distinctive fringed cap, smooth chestnut skin, and characteristic green mark at the bottom, and the tree's shiny, deep green, loosely-lobed leaves are attractive. But its bark is the cork oak's claim to fame. Almost ghostly pale in color, the bark is deeply furrowed and springy, and provides an ecologically sustainable cash crop. The thick, insulating bark also makes it possible for the tree to survive fires, after which it regrows branches to fill out the canopy.
Modern uses aside, the method of harvesting the bark from the cork oak dates back to the Middle Ages, using an axe that has barely changed in all that time. Virgin (or “male”) cork is cut for the first time from trees about 25 years old. After that, the bark is harvested every 9 to 12 years. Trees can live over 200 years, and one harvest of bark from a single tree can produce enough to cork 4,000 bottles.
In the harvesting process, the bark is peeled from the tree by hand, using only an axe to strip the bark from around the tree. Absolutely no machinery is employed. It can take up to five people to harvest the bark of each tree. Because expertise and finesse is required to peel off the bark without damaging the trunk's cambium layer, harvesters train for about 8 years.
Our cork oaks in Lower Bidwell park were also harvested periodically; scars from a stripping performed in 1940 and again more recently are visible even now.
In addition to providing cork bark, cork oak groves in Portugal and Spain support another form of agriculture: their acorns provide sustenance to sheep, cattle, and especially hogs. A superior type of ham with a distinctive sought-after flavor is obtained from the Iberian pigs that feed on the fallen acorns.
Our local cork grove in Lower Bidwell Park provides a window into the past by hearkening back to the ancient farming traditions of the Mediterranean countries, and is a living legacy to John Bidwell's quest to, as local naturalist Rex Burress elegantly stated, grow plants “far from their native origins but brought together to mingle in a new habitat.” Best of all, in my opinion, is our cork oak grove's genetic bond to those trees that make a crucial contribution to good wine.
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: Lauren Fordyce
The glassy-winged sharpshooter is a large leafhopper that can transmit several important, often fatal, plant diseases in California. This includes Pierce's disease of grape, alfalfa dwarf, almond leaf scorch, and mulberry leaf scorch. Pierce's disease is of most concern in California since the state accounts for about 94% of U.S. grape production.
Pierce's disease of grape has been reported in many counties throughout California. View a map of the current distribution of the pathogen. Glassy-winged sharpshooter adults are ½ inch long and dark brown to black with light-colored spots on their heads. Eggs are laid in masses under the leaf surface, resembling a greenish blister. Once the eggs hatch, the egg mass turns brown and remains as a scar on the leaf.
What can you do?
Glassy-winged sharpshooter feeds on many woody plants as well as annual and perennial herbaceous plants. It is common to find this invasive insect on acacia, avocado, eucalyptus, citrus, crepe myrtle, heavenly bamboo, grape, photinia, pittosporum, hibiscus, periwinkle, xylosma, some roses, and many others. Inspect plants for this pest, especially new shoots or growth. Use yellow-sticky card traps to monitor their populations.
If you find glassy-winged sharpshooter in an area not currently known to have this pest, immediately call the California Department of Food & Agriculture Pest Hotline at 1-800-491-1899, or contact your local agricultural commissioner's office.
To learn more about this pest and the diseases is transmits, visit Pest Notes: Glassy-winged Sharpshooter.
- Author: Kathy Keatley Garvey
If you're struggling with triple-digit temperatures, think about the honey bees.
They need to collect water for their colony to cool the hive so their brood can develop. And for other purposes.
Just call them "The Water Girls."
Lately the bees have taken a liking to our birdbath. The birds? They're practicing social distancing.
We remember Extension apiculturist Eric Mussen (1946-2022) telling us "Like most other animals, the bodies of honey bees are mostly water. Thus, they need to drink water routinely as we do. Additionally, water (or sometimes nectar) is critical for diluting the gelatinous food secreted from the head glands of nurse bees, so that the queen, developing larvae, drones, and worker bees can swallow the food. They use water to keep the brood nest area at the proper relative humidity, especially when it gets hot and dry outside the hive. Water droplets, placed within the brood nest area, are evaporated by fanning worker bees and that cools (air conditions) the brood nest area to keep the eggs and developing brood at the critical 94 degrees Fahrenheit required for proper development."
Unlike us, honey bees cannot simply turn on a faucet. "They will fly up to nearly five miles to find a suitable watering source," Mussen told us back in 2014. "Suitable to honey bees might not be suitable to us, but if it is moist, it may be visited. Suitable to the neighbors is a separate question. Honey bees can become quite a nuisance if they visit drippy irrigation lines or hose connections, birdbaths, pet water dishes, swimming pools, fountains, or wet laundry and the like. The water foragers become habituated to those sites. If you try to dissuade the bees by drying up the source for a while, it becomes evident that the bees will visit the site every so often so they'll be around quickly after the water is returned."
What to do? "People have tried to use repellents in the water, but the bees are likely to use the odor as an attractant when attempting to relocate the water source. Some people have had success keeping bees and wasps out of their swimming pools with very lightweight oils or monomolecular films--their purpose is to prevent mosquitoes from being able to breathe. But, if the water is splashed very much, you'll require a new layer."
And all those bees struggling in your swimming pool? "Not all moribund honey bees in a swimming pool are there because they were trying to get a drink. Every day, approximately 1,000 old honey bees from each colony die naturally. This normally occurs during foraging, and the bees just flutter down to the ground, sidewalk, driveway, parking lot, or whatever they were passing over. Some flutter into swimming pools. They are not dead, yet, so they can and do inflict stings on people who bump into them on the surface of the water. "
Beekeepers should make sure there's a watering source on their property so the bees won't hunt for water elsewhere, Musssen pointed out. It should be available all year around. "Once the bees are habituated to the site, most of them will use that source."
It's also a good idea to place corks in a birdbath for the bees to stand on. Bees don't like to get their feet wet. And if they drop into the water structure, they can drown.
As for the bee tenants in our watering hole, bring 'em on.
We absolutely love "The Water Girls." The birds, well, not so much. (But they do have access to a second birdbath and a fish pond.)