- 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 firstname.lastname@example.org.
Examples of neonicotinoid ingredients found in common garden insecticides:
- 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 email@example.com.
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 firstname.lastname@example.org.
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
- Author: Brent McGhie
By Brent McGhie, UC Master Gardener of Butte County, May 31, 2019
The University of California recommends the use of Integrated Pest Management (IPM) to control garden pests. The goal of IPM is to use the least harmful control method(s) that will be effective in managing a particular pest. Depending on the pest, these methods include one or more of the following: cultural controls, biological controls, mechanical and physical controls and chemical controls (pesticides). When using IPM, it is recommended that gardeners resort to the use of pesticides only as a last resort, after other control methods have been tried and found wanting.
Once the decision to use a pesticide has been made, the next step is to choose the right pesticide. The University of California Pest Notes series is a good source of information for identifying the least toxic pesticides appropriate for a specific pest. Low toxicity pesticides include insecticidal oils and soaps as well as the microbial insecticide, Bacillus thuringiensis, which is effective against many caterpillars, but nontoxic to other animal life. Pest Notes are available from your local UC Master Gardener program (based at the UC Cooperative Extension Office) and online at the UC Statewide IPM Program website.
Whenever a pesticide is used, all instructions should be read and carefully followed. Especially critical are instructions concerning proper application and safety precautions (for example, the use of protective clothing and eyewear).
The only legal way to dispose of pesticides is to take them to a local hazardous waste disposal facility. Do not pour unused or excess material down the drain, onto the soil, into waterways, into gutters, or into the trash. However, in California it is legal for homeowners to dispose of empty pesticide containers in the trash. Before disposing, containers should be triple rinsed and the rinse water used as part of the last application. To find the location of the closest hazardous waste disposal site, call the California Environmental Hotline (1-800-253-2687), or visit the “Earth911” website.
Information in this article is based on “Pesticides: Safe and Effective Use in the Home and Landscape” from the UC IPM website (Pest Note #74126).
For more information on gardening in our area, visit the UC Master Gardener of Butte County webpage at: http://ucanr.edu/sites/bcmg/. If you have a gardening question or problem, call our Hotline at (530) 538-7201 or email email@example.com.
- Author: Laura Lukes
By Laura Lukes, UC Master Gardener of Butte County, May 17, 2019
A beautiful tree sits on the north side of Little Chico Creek, shading the picnic table at site #34 in Lower Bidwell Park. Its thick, smooth lower branches are perfect for climbing, and its form is both rounder and more symmetrical than its relatives at higher elevations. And its occurrence at our low altitude (elevation 197 feet) is rare.
Captain George Vancouver of the British Royal Navy commanded a voyage of exploration and diplomacy from 1791 to 1795 which circumnavigated the globe and made contact with five continents. Madrone's species name honors the Scottish surgeon, botanist and naturalist, Archibald Menzies, who noted this tree during Vancouver's voyage of exploration. Menzies, who spent many years at sea serving with the Royal Navy and on private merchant ships, recognized its similarity to the European arbutus, A. unedo, which today is a popular landscape tree in Chico. Its red fruits are shaped like strawberries, and in fact the Spanish word madroño translates as “strawberry tree.” Other common names include madroa, madroo, madroña, and bearberry.
The madrone has evolved an effective method of seed regeneration: each berry contains between three and 30 seeds, and when the berries dry they develop hooked barbs that can latch onto the fur and skin of passing mammals, hitching a ride to colonize new locations.
The Pacific madrone ranges in height from about 33 to 82 feet but can reach up to 100 feet or more in ideal conditions. In those perfect conditions, it can reach a thickness of 5 to 8 feet at the trunk, much like an oak tree. Ideal conditions include a sunny site such as a south or west facing slope with soil that is well drained and lime free.
The largest known specimen of Pacific madrone lived in Joshua Creek Canyon Ecological Reserve on the Big Sur Coast. At least 125 feet tall and more than 25 feet in circumference, and listed on the American Forests National Big Tree list, it sadly was severely burned in the 2016 Soberanes Fire.
A massive, wide-spreading root system increases its ability to withstand summer drought. In fact, the tree prefers dry, well-draining soils and does not tolerate direct watering during the summer months. Once established, Pacific madrone is windfirm, drought enduring, and somewhat tolerant of wet, freezing conditions.
Pacific madrone is a particularly beautiful tree, with its reddish curved trunks supporting a broad, spreading crown of deep green leaves. It is most often seen as a single specimen tree displaying its finery among the more common Douglas fir and tanoak. It is currently declining throughout most of its range, unfortunately due to 100 years of forest fire control and urban development in its native habitat. We are lucky to have our lovely, rare specimen in Lower Bidwell Park.
For more information on gardening in our area, visit the UC 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 firstname.lastname@example.org.