The Real Dirt Blog - Agriculture and Natural Resources Blogs

sitenum=298

Neonicotinoids and Pollinators: Why You Should Read the Label

Author: Jeanette Alosi

Published on: July 12, 2019

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.

Swallowtail on tithonia by J. Alosi

Studies conducted by the Bee Informed Partnership, the Xerces Society, and other groups indicate a combination of factors have contributed to honeybee losses. Factors include: habitat loss; drought; poor nutrition; parasites such as Varroa mites; pathogens such as fungi and viruses; and exposure to pesticides. While research initially focused on honeybees, more recent studies focused on native bees and other pollinators, specifically the role played by a class of pesticides called neonicotinoids (neonics).

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.

Buckeye butterfly on paprika yarrow by J. Alosi

In a number of cases, neonics have been implicated in mass die-offs of native bumblebees: for example, a mass die-off of bumblebees in Oregon has been attributed to an application of a neonic pesticide on linden trees.. This has spurred additional research on native pollinators, and we now have a better understanding of how neonics travel in our plants, soil, air and water. This new research led the U.S. Fish and Wildlife Service to phase out neonic use on National Wildlife Refuges in 2016. In 2018, the European Union banned all outdoor use of several neonics. (See, for example, the Xerces Society report How Neonicotinoids Can Kill Bees: The Science Behind the Role These Insecticides Play in Harming Bees, 2016).

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.

Anna's Hummingbird by J. Alosi

The neonics have several characteristics that are causing alarm. They are systemic pesticides, meaning they are absorbed into a plant's tissue. Systemic pesticides can be applied in a number of ways: by drenching the soil; injecting directly into plants; used as a spray; and applied as a seed coating. As these pesticides are absorbed, plant tissue, pollen and nectar become toxic. Pollinators who visit flowering plants to collect pollen and nectar are then exposed to the pesticide. The Xerces Society report noted above states that even small levels of neonics can affect the ability of bees to navigate and impair their sense of taste. These are important factors in their ability to forage for food.

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.

Honeybee on Ray Hartmann ceanothus by J. Alosi

In addition to agricultural crops, native flowering plants also depend upon pollinators. The Xerces Society argues that fewer pollinators may lead to a decrease in native flowering plants and the wildlife that depends upon those plants (Chapter 1, “Why Care About Pollinators?” in Attracting Native Pollinators: Protecting North America's Bees and Butterflies, Xerces Society, 2011).

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.

Patch of pesticide-free California poppies by J. Alosi

What can you do to help? Read the label! Avoid using systemic neonic products in your garden by checking the active ingredients listed on pesticides and fertilizers. Ask local nurseries if plants or seeds they sell are treated with a neonic product. Several major home and garden retailers have already agreed to eliminate neonic-treated plants from their nurseries. When applying a fertilizer avoid fertilizer-pesticide combinations because many of them contain neonics. If worm control is warranted, turn to an organic pesticide such as Bt (only effective on worm pests). Practice Integrated Pest Management (IPM) techniques to control garden pests (see http://www.ipm.ucdavis.edu/). Remember that chemical pesticides can affect all insects, including ladybugs and other beneficial insects that keep destructive pests such as aphids under control.

Patch of pesticide-free flowering plants by J. Alosi

Most importantly, create a pollinator-friendly garden by planting patches of pesticide-free flowering plants. Try to provide food sources for pollinators throughout the year. The Xerces Society is a great resource for more information on the dangers of neonics and how to create a pollinator-friendly garden: http://www.xerces.org.

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:

Imidacloprid
Clothianidin
Thiamethoxam
Acetamiprid
Dinotefuran

Focus Area Tags: Yard & Garden

Tags: Butte County Master Gardeners (31), imidacloprid (1), neonicotinoids (2), Neonics (1), pollinators (2)

Local Trees: The Redbud is No Plain Jane

Author: Laura Lukes

Published on: June 28, 2019

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 near Briceberg by LaurentianShield

The redbud's Latin name, Cercis, is equally pedestrian: it is taken from the Greek kerkis which means “a weaver's shuttle” and refers to the shape of the tree's seed pods. Both the tool and the seed pods (which are essentially fruits) are elongated ovals with gently pointed ends. Cercis is a member of the Fabaceae or pea family (technically a legume) and it bears the family resemblance both in its fruits, which in shape and size are dead ringers for snow peas, and in its flowers.

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).

Cercis occidentalis blossom close-up by Allicon Garcia

Enough fun with words: the focus here is on the Western redbud. This species is found in Arizona, California, Nevada, and Utah. It typically is a small deciduous tree, more often a shrub, rarely reaching over 20 feet in height. A notable exception to that is a C. occidentalis in Santa Rosa that is registered as a California Big Tree. It measures 45 feet high, has a trunk circumference of 71 inches, and a crown spread of 38 feet. Most specimens grow multi-stemmed trunks and develop a low, spreading, rounded or umbrella-shaped canopy of 10 to 20 feet in diameter. The Western redbud boasts a wildly variable life span, from 40 years all the way to 150.

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.

Cercis occidentalis leaves and seed pods by John Comeau

Regionally, redbud takes root in the foothills and mountains of California. Locally, it dots the hillsides in Upper Bidwell Park and the western Sierra Nevada and Cascade foothills. One of its more striking attributes is its penchant for solitude, which is what makes it such a vibrant surprise when it blooms in late February/early March. Very seldom will it grow in groups or shrubby clumps, and then only in sheltered niches.

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.

Cercis occidentalis seed pod close-up by John Rusk

The straight, pliable, burgundy-colored young shoots of the California redbud were prized by native basket weavers. Designs were woven into baskets with redbud shoots, and a faint reddish dye derived from the bark was used to tint finished baskets. To ensure a reliable supply of this valued material, California tribes regularly burned hillsides in the fall, after the redbuds had shed their leaves. Prior to European settlement, the western Mono, foothill Yokuts, and Miwok Native Americans of the central and southern Sierra Nevada foothills set autumn fires at intervals of one to several years to encourage sprouting. Today's basket artists prune the shrubs to encourage the new growth.

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

Focus Area Tags: Yard & Garden

Tags: cercis occidentalis (1), Redbud (1), redbud seedpods (1), Western redbud (2)

Local Trees: The Enchanting Dogwood

Author: Laura Lukes

Published on: June 14, 2019

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.

Cornus florida closeup of pink flower by Famartin

There are between 30 and 100 different species of Cornus (depending upon the source one consults). These various species of dogwood are native throughout much of earth's temperate latitudes and boreal (subarctic) ecosystems of Eurasia and North America. China, Japan, and the southeastern United States are particularly rich in native species. The best known and most widely cultivated dogwood species include: common dogwood (C. sanguinea) of Eurasia; flowering dogwood (C. florida) of eastern North America; Pacific dogwood (C. nuttallii) of western North America: Kousa dogwood (C. kousa) of eastern Asia, and two low-growing boreal species, the Canadian and Eurasian dwarf cornels (or bunchberries), C. canadensis and C. suecica respectively. This article focuses on two species that do particularly well in our area: Pacific dogwood and flowering dogwood.

Flowering dogwood bracts by UC ANR

General Characteristics: Dogwood trees are on the small side, ranging between 15 to 40 or so feet high. Typically, trunks are one foot or less in diameter, and often sport multiple stems. They provide four full seasons of delight: spring flowers, summer leaves, fall color and berries, and once all of those have dropped off in winter, the trunk displays a distinctive patterned bark and a pleasing rounded form with horizontal branching.

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.

Cornus florida or Eastern dogwood by Brent McGhie

Cornus florida: The flowering dogwood is a popular landscape tree throughout the United States, and is commonly seen here in Chico and our surrounding area. The species name florida or florido is Spanish for “full of flowers” or “flowery”. Native to the Eastern US and northern Mexico, flowering dogwood attains its greatest size, up to 40 feet tall, in the Upper South where hot, humid summers contribute to new, lush growth. In other climates, such as ours, heights of 30–33 feet are more typical. This dogwood species' life span tops out at about 80 years. While its berries, ranging from bright red to yellow with a rosy blush, taste awful to humans, they are not toxic, and are an important source of food for many birds.

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.

Cornus nuttallii-closeup of flower by Walter Siegmund

Cornus nuttallii: The species name of the Pacific dogwood honors Thomas Nuttall, an English botanist and zoologist who lived and worked in America from 1808 to 1841. Nuttall travelled widely and published a number of books on North American plants and birds. Almost 100 plant and animal species bear his name.

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.

Cornus nuttallii in bloom by Stan Shebs

Pacific dogwood thrives under the canopy of California's mountain forests. When in bloom, flowers hover like lace in the shadows of taller conifers and hardwoods, reaching out for sunlight. While the bracts appear white from a distance, they are actually white tinged with a lovely pale green, and the densely packed, tiny flowers they encircle are also greenish-white. The pink-red drupe can contain up to 100 seeds. The fruit provides sustenance in autumn and sometimes early winter, to small mammals and birds such as grosbeaks, cedar waxwings, and woodpeckers.

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.

Stellar Pink, a cross between a florida and kousa by J. Alosi

Dogwood is a curious name for a tree. But “dogwood” is actually this tree's third-generation common name. In the 14^th century it was called the “whipple-tree” – a whipple being a straight piece of wood linking the drawpole of a horse cart to the harnesses of the horses. By the early 15^th century the name had shifted to “dagwood,” because its slender and very hard wood stems were used to create “dags” (daggers, skewers, and arrows). Over time, the “a” in “dagwood” became pronounced and written as an “o,” giving us “dogwood” as the final common name for all species of Cornus.

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

Focus Area Tags: Yard & Garden

Tags: bracts (1), cornus (1), dogwood (1), florida (1), nuttallii (1), small trees (1)

Using Pesticides in the Garden

Author: Brent McGhie

Published on: May 31, 2019

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.

Sample ingredient label, ANR

Before using a pesticide, be certain a pest is the actual cause of the problem you are experiencing. For example, plants can be damaged by incorrect watering, poor drainage, accidental herbicide exposure, or physical damage from wind, hail, sun scorching and other weather-related factors. A decision should also be made on how much damage you are willing to tolerate. Minor surface blemishes on fruit caused by thrips are probably an acceptable alternative to pesticide use. Once it has been determined a pest is present and is causing a major problem, identify the pest and research alternative control methods. If you need help, your UC Master Gardeners of Butte County can provide guidance in these areas. In most cases, even if a pesticide is utilized, a combination of measures will provide the best long-term control.

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.

Protective goggles used to protect eyes during mixing and applying pesticides, ANR

Before purchasing a pesticide read the label to be certain the plant you plan to use it on is listed on the label. Never use pesticides designated for use on ornamental plants on plants that will be eaten unless they are also listed on the label. Also, be aware that most pesticides only control certain stages of a pest's life cycle. For disease control it is important to remember that fungicides are preventive and, although they may slow the progress of an existing infection, they will not eliminate it. Herbicides may be pre-emergent (preventing weeds from germinating successfully), or post-emergent (designed to kill actively growing weeds). Herbicides may also be broad-spectrum (killing weeds of almost any type), or selective in the type of weeds they affect.

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).

Adult earwig, ANR

To minimize pesticide contamination of the environment, mix only what is needed for immediate use and never use more than what the directions recommend. To further limit environmental exposure, avoid widespread applications; instead, apply only to affected areas. Do not spray during windy conditions when pesticides can be blown away from their intended target. To prevent contamination of waterways, avoid spraying near storm drains, creeks, or other bodies of water. It's important that the application dry on the target before it gets wetted by rain or irrigation. Unless otherwise specified, do not spray just before irrigating, or before rainy weather. Additionally, be aware that spraying pesticides on hard surfaces such as foundations, driveways or sidewalks increases the likelihood that they will be washed off into storm drains.

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 mgbutte@ucanr.edu.

Focus Area Tags: Yard & Garden

Tags: Butte County Master Gardener (39), integrated pest management (3), IPM (3), pesticides (1)

Local Trees: The Pacific Madrone – Rare in Lower Bidwell Park

Author: Laura Lukes

Published on: May 17, 2019

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.

Madrone in Lower Bidwell Park by Laura Lukes

Arbutus menziesii, a broadleaf evergreen hardwood tree, is best known as Pacific madrone. It is most often found along Puget Sound, and in the Oregon and California coast ranges; it is also scattered on the western slopes of the Sierra Nevada and Cascade mountain ranges. Its favorite habitats in southwestern Oregon and northern California are dry foothills, wooded slopes, and canyons. In California, madrone grows best at elevations between 300 and 4,000 feet. If you've driven State Route 20 between Willits and the coast, you've seen these stately trees reaching above the coast redwood and mixed-evergreen forest canopy on the steeper slopes.

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.

Pacific madrones are usually tall and slender, reaching above the surrounding forest canopy by mindgrow from Schwalmtal, Deutschland

While all parts of the Pacific madrone are remarkable, its best-known characteristic is that it freely peels its outer bark. Once this skin-like outer layer is shed, the remaining bark is smooth and polished, with a distinctive reddish color. Young bark darkens to a deep red with age; younger stems can range from green to chartreuse, and young trunks are frequently orange. Older portions of the bark become a dark, brownish red. The deep color of the bark contrasts nicely with the tree's large, glossy, dark green foliage. In spring, sprays of small, bell-shaped white flowers adorn the branches, giving way to red berries in the autumn months.

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.

Madrone in Lower Bidwell Park. Low, horizontal branches are tempting to climb by Laura Lukes

Surviving Drought and Fire: At the base of its trunk, the Pacific madrone has a woody, globe-shaped, regenerative organ known as a burl. This structure is a peculiar adaptation to its forest habitat, which historically experienced regular burns at intervals averaging between 10 and 35 years. The Pacific madrone is susceptible to fire, but also relies on fire to regenerate. Its low resistance to fire is due to its thin bark. Conversely, repeated top-kill by fire encourages burl development, enhancing Pacific madrone survival - the burl serves as a source of stored carbohydrates for prolific postfire sprouts. These rise from dormant buds on the burl, and initially grow rapidly after a 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.

Burl at the base of Pacific madrone by Thewellman Commons Wikimedia

Native American Uses: The Concow tribe calls the tree dis-tā'-tsi or kou-wät′-chu. Native Americans sometimes ate the berries, but were more likely to make them into a type of cider, or chewed them to cleanse their mouths, since the berries' high tannin content makes them astringent. Madrone berries were used in necklaces and other decorations, and as bait for fishing. Tea made from the bark and leaves was used to treat stomach aches, cramps, skin ailments, and sore throats. The wood was used to make implements and it was particularly useful as firewood; its density and hardness ensures it burns long and hot -- even better than oak.

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 mgbutte@ucanr.edu.

Focus Area Tags: Yard & Garden

Tags: Arbutus menziesii (1), Butte County Master Gardener (39), Pacific madrone (1)

Next 5 stories > Last story >>

Viewing 1-5 of 34