- Author: Laura Lukes
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.
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.
What makes the cork bark commercially viable is its unique cell structure and its ability to regenerate. A cubic centimeter of cork bark is teeming with air cells (up to 40 million!) and those cells are waterproofed by the waxy suberin. Cork oak bark is durable, light, and bouncy, and once cut, has a suction-cup effect that helps it adhere to the neck of a bottle. There is a long list of uses for cork that's left over after the stoppers have been cut out: flooring, cricket ball cores, insulation panels, sound-proofing materials, fishing rod handles, even devices for the space industry. In Portuguese towns and cities, it is common to see shops selling backpacks, handbags, and even shoes made out of cork.
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. Click here for a photo taken in 1941 of the local cork oak trees.
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.
The Butte County UC Master Gardeners are part of the University of California Cooperative Extension (UCCE) system, serving our community in a variety of ways, including 4H, farm advisors, and nutrition and physical activity programs. Our mission is to enhance local quality of life by bringing practical, scientifically-based knowledge directly to our community. For more information on UCCE Butte County Master Gardeners and their upcoming events, and for help with gardening in our area, visit https://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.
Photo Credits:
Cork oak acorns - Bellotas de alcornoque (Quercus suber), Ceuta, España. Xemenendura - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29528312
Cork oak stripping - Nederlands: Kurkschillen in Santa Margarida da Serra. By Nocampo - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=23045407
Trunk of a Cork oak - Stamm einer Korkeiche (Quercus suber). By Claus Ableiter - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2170249
Cork Oaks Southern Portugal. By KirjavaKinkytail - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=79311214
- Author: Cindy Weiner
By this time of year the lush growth and colorful flowers of spring are just a memory.
Eriogonum, or wild buckwheat, is a large genus with many species native to California. These perennials are available in a variety of sizes, growth habits and flower colors, and some species also have named cultivars. Individual flowers are small but are born in clusters containing many flowers, providing a visual impact. Wild buckwheats are very attractive to native pollinators, especially butterflies, and also provide food and habitat for birds. The flowers are long-lasting, fading to a rusty color in late summer. The plants are evergreen, grow in full sun, and require little to no supplemental water once established.
California buckwheat (Eriogonum fasciculatum) is native to the foothills of southern California and is quite drought-tolerant. It grows one to three feet tall and up to four feet wide. Its needle-like leaves grow in clusters along the stem. The white or pink flowers grow in flat-topped clusters.
St. Catherine's lace (Eriogonum giganteum) is native to the Channel Islands and Baja California. It grows to be a large, rounded woody shrub four to five feet tall and six or more feet wide. Its creamy flowers grow in large flat clusters held above the plant. The leaves are gray-green and felty.
The Butte County UC Master Gardeners are part of the University of California Cooperative Extension (UCCE) system, serving our community in a variety of ways, including 4H, farm advisors, and nutrition and physical activity programs. Our mission is to enhance local quality of life by bringing practical, scientifically-based knowledge directly to our community. For more information on UCCE Butte County Master Gardeners and their upcoming events, and for help with gardening in our area, visit https://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.
- Author: Jeanette Alosi
The decline in numbers of European honeybees, bumblebees and other native pollinators has been well documented for over a decade. Research exploring pollinator decline began in earnest in 2006 when Colony Collapse Disorder, affecting honeybees, first appeared. In 2006 and 2007 managed honeybee colonies experienced a loss rate of over 30 percent. There was great concern that the loss of pollinating honeybees could negatively affect agricultural production including our local almond crop. Although managed honeybee colonies rebounded (thanks to improvements in hive management), hive losses from April 2018 to April 2019 reached 40%, the highest loss since monitoring began, primarily due to reduced effectiveness of Varroa mite control materials.
Neonics are a nicotine-derived class of pesticides developed for use on both farm crops and landscape plants. Approved by the EPA in the 1990's, this group of neurotoxins are the most commonly applied group of insecticides in the world.
No direct link has been found between neonics and the Colony Collapse Disorder of honeybees. Although not clearly understood, neonics may weaken the honeybee immune system, thus making the bees more susceptible to pathogens and diseases. Research has also found that bumblebees and solitary bees are affected differently than honeybees. A study at Worcester Polytechnic Institute in Massachusetts discovered that queen and male bumblebees suffer much higher rates of mortality compared to that of worker bees. This negatively affects the ability to form new colonies.
Neonics are long lasting; they can persist in the soil for months, but can last years in woody plants. When used to protect corn and other seeds, they can remain in the soil to be absorbed later by other untreated plants.
Because many products approved for home and garden use can be legally applied at rates significantly higher than the rates approved for agricultural crops, home gardeners may unwittingly be exposing pollinators to toxic levels of pesticide. Neonic pesticides found in common home and garden products include imidacloprid, clothianidin, thiamethoxam, acetamiprid, and dinotefuran.
The Butte County UC Master Gardeners are part of the University of California Cooperative Extension (UCCE) system, serving our community in a variety of ways, including 4H, farm advisors, and nutrition and physical activity programs. Our mission is to enhance local quality of life by bringing practical, scientifically-based knowledge directly to our community. For more information on UCCE Butte County Master Gardeners and their upcoming events, and for help with gardening in our area, visit https://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.
Examples of neonicotinoid ingredients found in common garden insecticides: |
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- Author: Laura Lukes
Redbuds in bloom are a most welcome harbinger of spring. Their dense clusters of magenta flowers bloom early, providing splashes of color against a winter landscape of browns and grays. Is the name redbud really the best our ancestors could come up with for this beautiful tree? How could they call that color “red”? Even Wikipedia manages a more accurate “pink to purple.” Other sources are more specific, identifying the brilliant flora as bright pink, rosy pink, magenta, or reddish purple.
Cercis occidentalis is native to the arid western states. It is commonly known as Western or California redbud, and sometimes Arizona redbud. Occidentem is Latin for “western sky” or “part of the sky in which the sun sets,” derived from the Latin verb occido – “go down, set.” The Occident is the longitudinal opposite of the Orient, and many species from China and other eastern regions are termed orientalis. Somewhere along the line, C. occidentalis acquired the second or synonymous binomial C. orbiculatum. Orbiculate translates naturally enough as round or circular in shape (in this case, in reference to the redbud's leaves). And if you are thinking now of Judas Tree as a common name, that belongs to the Eastern redbud. (Interestingly, the Latin name of the Eastern redbud is C. canadensis. And yes, you guessed it: canadensis is used in taxonomy to denote species indigenous to or strongly associated with Canada).
A hardy plant, the redbud is drought tolerant, sun-loving, and successful in a variety of soils. Typically, it prefers rather harsh environments with marginal, well-drained soils. It grows best in chaparral ecosystems below 4,000 feet in elevation, and prefers canyon walls and other steep slopes. It can also be found in gravely and rocky soils along streams above their flood zone. Western redbud tolerates some seasonal water and will grow in the bottom of ephemeral streambeds in little pockets, as well as on foothill benches, or tucked into crannies created by boulder outcroppings.
Western redbud is a popular landscape tree on the valley floor precisely because of its impressive beauty, which isn't restricted to eye-catching floral displays. The rounded, heart-shaped leaves are a silky combination of copper and green when they first emerge, darkening to various shades of green, gray-green, or blue-green. According to the USDA, the Western redbud's “autumn display of yellow turning to red and brown rival that of some eastern hardwoods.” This plant sets its fruit in the form of thin dry seed pods in autumn. Each pod contains about seven hard, bean-like seeds. As they ripen, the pods change in color from purple to russet brown. (On some redbuds, the mature pods hang on the branches into the next winter.) Once the redbud has shed itself of leaves and pods, the bare branches provide winter beauty as a silver-gray silhouette.
As a legume, redbud is an edible native. Native Americans enjoyed redbud flowers, young seed pods, and even young leaves, both raw and cooked. Apparently, redbud flowers taste almost as good as they look. Fully-opened flowers are somewhat tart and slightly sweet, and add interesting color and flavor (and Vitamin C!) to salads.
This beautiful and hardy native shrub is nowhere near as dull and plodding as its common name implies. While the redbud makes year-round contributions to the landscape, the Arbor Day Foundation correctly notes that “the sheer springtime beauty of the redbud may be its greatest hold on the American spirit.”
For more information on gardening in our area, visit the Butte County Master Gardener webpage at: http://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.
Photo Credits:
Cercis occidentalis blossom close-up by Allicon Garcia: https://ucanr.edu/repository/view.cfm?article=166638%20&search=Cercis
Cercis occidentalis near Briceberg by LaurentianShield - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=78098719
Cercis occidentalis leaves and seed pods by John Comeau - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26493957
Cercis occidentalis seed pod close-up by John Rusk from Berkeley, CA, United States of America - H20150416-0002—Cercis occidentalis—RPBG, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=59290592
- Author: Laura Lukes
Local Trees: The Enchanting Dogwood
Ideally, you'd be reading this in very early spring, when the dogwood bloom is beginning to work its elegant magic in the older neighborhoods fanning out from Lower Bidwell Park and downtown Chico. Their flowers bloom before dogwoods leaf out, so the blooms appear to float, suspended on slender, graceful branches. But now, although their bloom time is over for the year, the new foliage on dogwoods makes them attractive landscape trees, creating filtered shade in gardens and yards across town.
What we see as “flower petals” on the dogwood are technically bracts (modified or specialized leaves) surrounding a bunch of very small, tightly clustered umbel shaped flowers. The leaf itself is a simple, untoothed bit of beauty, distinctive for its visible veins curving as they extend to the margins of the leaf. In fall, the leaves change to an attractive reddish-purple or reddish-brown before dropping. Its bright colored berries are actually drupes, a fleshy fruit with thin skin and a central stone containing multiple seeds. These “berries” provide food to many bird species, and are also utilized by some butterflies and moths. Depending on the species, berries range from very tart and mildly toxic to humans, to tasteless, to slightly sweet and somewhat palatable.
When in the wild, flowering dogwood can typically be found decorating the understory of forest edges, and can also occur on dry ridges. Most of the wild trees have white bracts, but some range from pink to rosy to an almost true red.
Nuttall's namesake dogwood species is commonly known as western dogwood, mountain dogwood, and Pacific mountain dogwood, as well as Pacific dogwood. This species is native to a large swath of western North America, sweeping down the continent from southern British Columbia to southern California, with an isolated population cropping up in central Idaho. On a California map, its distribution pattern looks like a large cane. The short, hooked end starts in the coast range north of the San Francisco Bay, thickening as it bends east through the Klamath and Siskiyou mountains, with the straight side of the cane extending south through the western slopes of the Cascades and Sierra Nevada mountains to the southern end of the great Central Valley. A small distribution also occurs in the southwestern corner of the state.
Besides its timeless aesthetic appeal, the Pacific dogwood has various utilitarian functions. It was an important plant for the Native tribes of the continent's west coast. Medicinally, the bark was used as a laxative, a tonic, an antiseptic, and for relief of stomach pain. Peeled twigs provided natural toothbrushes, and smaller branches were sometimes used in baskets. Today the wood of the Pacific dogwood is often used for fashioning items such as tool handles and cutting boards because of its hard, strong wood and beautiful tight grain. It has also been used to make thread spindles, golf club heads, and piano keys.
I love the ethereal beauty of the dogwood. Since a large number of cultivated dogwood trees grace our area, evidently so do many others. In fact, dogwood was among the top choices for America's National Tree in a nationwide survey hosted by the Arbor Day Foundation, coming in third behind the oak and redwood: a very respectable ranking!
For more information on gardening in our area, visit the Butte County Master Gardener web page at: http://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email mgbutte@ucanr.edu.
Photo Credits:
Cornus nuttallii in bloom by Stan Shebs: http://commons.wikimedia.org/wiki/User:Stan_Shebs
Cornus nuttallii closeup of flower by Walter Siegmund - The small flowers are in a dense cluster surrounded by large white bracts. Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1724799
Cornus florida closeup of pink flower by Famartin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=28041080
Flowering dogwood bracts by UC ANR
Cornus florida or Eastern dogwood by Brent McGhie
Stellar Pink, a cross between a florida and kousa dogwood by J. Alosi