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.

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. 

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.

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.

Native American Uses: The Concow tribe calls the tree dis-t?'-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.

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.

Summers are getting hotter in much of the U.S., including our local environment.  One way to counteract this change in climate is by planting trees to provide more shade in the summer months.  But adjusting to a shadier garden also means shifting to different plant choices.  While it is true that most colorful garden flowers (like roses, zinnias, poppies, and hollyhocks) require full sun, there are still many options for blooms available to the shade gardener.  White flowered gardenias and pink or blue flowering hydrangeas are common shade plants in our area.  Here are some less obvious selections of shrubs that are easy to care for and can provide interest in the shade garden at different times of the year:

A great small shrub for very shady areas is Sarcococca (sweet box).  It is evergreen, with dark green leaves and tiny white flowers that appear in late winter or early spring and are very fragrant.  Following the flowers are red berries.  Once established, Sarcococca will tolerate dry shade.  It is especially lovely planted in groups or as a small hedge; several of these shrubs growing together maximizes their scent, which has been compared to that of sweet vanilla.  S. ruscifolia is slow growing, but can eventually reach six feet tall and wide; S. hookeriana humilis is a much shorter shrub, growing to perhaps one and a half feet.  This variety will spread by underground runners to create a good ground cover over time.  Sarcococca is a perfect choice for deeply shaded areas under eaves and overhangs, alongside entryways, and under low-branching evergreen trees. 

For a spot in the garden that would benefit from some bright color in spring and early summer, consider Kerria japonica.  This is a deciduous shrub, but its bright yellowish-green stems provide color in the winter months.  Triangular bright green leaves emerge in early spring on thin arching branches, followed by golden yellow blossoms that resemble small roses about an inch in diameter.  K. japonica ‘Pleniflora' is commonly found in local nurseries.  It can grow eight to ten feet tall and wide, with graceful arching branches covered with double yellow blossoms.  Plant K. japonica in a partially shaded spot, where it will get at least four but no more than six hours of sun each day, preferably in the morning hours, or in the early evening after the hottest time of day.  After flowering is completed, cut the branches that have flowered back to the ground, allowing this shrub to retain its arching habit.

Some shrubs that require full sun in zones 7 or 8 can thrive in our hotter zone 9 climate if planted in a location with light shade.  This is the case with spring-blooming Deutzia, which is happy underneath a Japanese maple, for example, alongside azaleas and other acid-loving plants. There are numerous forms of this shrub, with either white or pink flowers.  D. ‘Magician' has spectacular pink flowers that appear along elegant, arching stems, and can grow up to six feel tall and as wide.

The genus Spiraea includes many species that do well in lightly shaded areas in our climate.  There are two main types of Spiraea:  those with long, graceful, arching branches lined with clusters of tiny white flowers (these are often referred to as the “bridal wreath type”); and those with a shrubby growth habit which produce clusters of white, pink or red blossoms at their branch ends.  Both types are deciduous, and the leaves of many of these species turn bright shades of red, orange, or yellow in the fall.

Spiraea thunbergii is a bridal wreath type that can reach six feet high and wide, with many thin, arching branches.  In early spring, the bare branches are lined with clusters of tiny white flowers.  These are followed by very narrow, inch-and-a-half-long, blue-green leaves that turn yellow or reddish brown in the fall.  Another stunning bridal wreath type is the fast-growing S. x vanhouttei. On this shrub, diamond-shaped blue-green leaves emerge first, followed by flat clusters of white blossoms covering the plant in mid to late spring. 

A notable shrubby type of Spiraea is S. japonica ‘Anthony Waterer.'  Reaching three to five feet high and wide, it produces two-to-three-inch wide clusters of deep pink blossoms in late spring and early summer, and will produce another crop of blossoms if spent flower clusters are reliably pruned out.  While ‘Anthony Waterer' has bright green foliage, similar pink-flowering varieties have been developed with quite remarkable leaf color.  For example, ‘Goldflame' and ‘Goldmound' have bright yellow-green foliage, and the leaves of ‘Limemound' emerge lemon yellow, then turn to lime green. 

By planting several different species of Spiraea, you can have blooming shrubs in shadier areas of the garden from early spring into summer, with the added bonus of beautiful fall-colored leaves, and often, brightly-colored bare stems in winter.

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.

Companion planting combines diverse plants in an informed manner to bring a balanced ecosystem into the garden.  This approach to gardening has been used by organic gardeners for decades.  The idea is to plant herbs and flowers with vegetables to create sustainable gardens with better crop yields.           

Diversity is one goal of companion planting.  Plants that are “companions” help each other grow—for example, tall plants provide shade for sun-sensitive plants.  Companions use garden space efficiently—vining plants can cover the ground, while tall plants grow upwards through their foliage. Using this method, companion plants are precisely placed for diversity as well as the benefits of plant health and insect disruption. One traditional plant pair is that of carrots and tomatoes, which are beneficial to one another (while, on the other hand, cabbages and tomatoes create an antagonistic combination).  To maximize space in the garden, lettuce, carrots, and onions can be planted together; their roots grow to different depths so they use water efficiently.

The “three sisters,” corn, beans, and squash, are perhaps the best-known example of ideal plant companions. They support one another's growth, maximize the growing area's crop yield, and provide a solid diet for their cultivators.

Another well-known group of companions is that of legumes (like beans), with clover and alfalfa.  Bacteria invade the root hairs of legumes and make nodules where these beneficial Rhizobium nitrogen-fixing bacteria live.  The nitrogen these bacteria fix becomes available to the legume plant and the soil around its roots.  Legumes can be worked into the soil, renewing and replacing nitrogen.  This reduces the amount of manure and chemical fertilizers needed for heavy-feeding plants.

Companions can help prevent pest problems by repelling pests or attracting the beneficial insects needed to keep down the population of insect pests.  Onions are one plant that repels some pests.  Marigolds contain thiophene, which deters root nematodes. Chives planted alongside roses repel aphids.  Nasturtiums act as a decoy crop for kale and tomatoes by attracting aphids away from the more desirable edibles (once the nasturtium plant has attracted aphids, it is removed from the garden before the aphid young develop wings).  Aromatic herbs like basil, rosemary, lavender, and sage, will repel many pests.  Mix these in with pest-susceptible plants.  The presence of diverse plant species disrupts the ability of herbivorous insects to discover host plants for feeding or egg-laying.  The time wasted on non-host plants reduces the reproductive efficiency of specialist insects.   

Companions of flowers and herbs attract beneficial insects.  Beneficials are predators or parasites of harmful insects.  Beneficials include ground beetles,ladybugs, praying mantids, and pirate bugs.  Some species of wasps, spiders, and flies are also beneficial. Plants that flower in umbels (flat-topped clusters of small flowers) such as dill, parsley, carrot, angelica and parsnip, provide habitat for beneficial insects.  For example, Queen Anne's lace is an excellent habitat for small predator wasps that lay their eggs in the bodies of aphids.

Lists of specific companion plant combinations can be found on websites and in gardening books.  Find the best friends for your garden plants, to create sustainable gardens with better yields.  Remember to experiment, observe and record how these companions work in your own garden.

PLANT SALE!  Mark your calendar for our plant sale on Saturday, May 18, 2024 from 9 am–noon.  The sale will be held at the Master Gardeners Demonstration Garden at Patrick Ranch.  The plants, which are selected to thrive in our climate, have been propagated by UC Master Gardeners of Butte County. For more information and a partial list of the plants that will available, visit our website.

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.

Next time you go for a walk in Upper Park, look closely at the different plants you see. Notice the enormous diversity of shapes, colors, and forms. There are trees, shrubs, perennials and annuals, all different shapes and sizes of leaves, and tremendous variation in flower color and structure from one species of plant to another. This diversity is the result of evolution over the ages. Plants have adapted to the specific conditions of their native habitat. These conditions include climate, availability of water, soil type, and interactions with other organisms. Adaptations can be structural or physiological.

Some plants have co-evolved along with their pollinators, resulting in flowers that have adaptations making them very suited to particular pollinators. There are more than 250 species of monkshood (genus Aconitum) worldwide. They are mostly found in moist meadows of mountainous area of North America, Europe and Asia. The flowers have structural adaptations to accommodate pollination by long-tongued bumblebees. Unlike most flowers, the sepals are not green but are the same color as the petals (usually blue). The 2 upper petals are large and tuck under a cylindrical “hood” formed by one of the sepals. This hood resembles a monk's hood of the Middle Ages. The petals have a hollow spur at their apex, which contains the nectar. Bumblebees are large and strong enough to open the flowers, crawl inside, and find the nectaries. The volume of the hood is large enough to accommodate the bumblebee as it crawls over the anthers and stigmas, picking up or depositing pollen along the way.

Plants that live in the desert have many adaptations to help them survive living in such a harsh environment. Some plants, like the barrel cactus, store water within the stems or trunk, and have spines or hairs that help shade the surface to cool the plant. Other plants, like the ocotillo, have small leaves that sprout quickly after a rainfall and fall off when the soil dries out. The ocotillo remains alive with partially green stems until the next rainfall. Blue palo verde (Parkinsonia florida) is a small multi-trunked tree with small compound leaves, bright yellow flowers, and green bark. Similarly to the ocotillo, the blue palo verde tree sheds its leaves when the weather is hot and dry. The tree doesn't go dormant at this time because photosynthesis also occurs in the bark. During the year, about two-thirds of the photosynthesis takes place in the bark and only one-third in the leaves.

The beavertail cactus (Opuntia basilaris) is a kind of prickly pear cactus. It lacks long spines but its flat, fleshy pads are covered with small bristles that have barbed tips. The bristles help shade the pads and also protect the cactus from being eaten. The pads themselves are modified stems. They have a waxy cuticle to reduce water loss and store water within. During periods of drought the pads shrivel and then plump back up when rain returns.

All plants have very small holes called stomata on the underside of their leaves.  The hole can open for exchange of carbon dioxide and oxygen gases or close to maintain the proper balance of water.  Most plants open their stomata during the day to take in carbon dioxide for photosynthesis. They close the stomata at night to retain water. Plants in the cactus family, plus some succulents and certain orchids, open their stomata at night and close them during the day. They have a modified photosynthetic cycle, called Crassulacean Acid Metabolism (CAM), which helps to reduce water loss during gas exchange. Carbon dioxide enters the open stomata at night when less water will be lost to the outside air. The carbon dioxide is then fixed and combined with another chemical to form an organic acid. The acid is then stored until the daytime when sunlight is available to finish the process of transforming it to sugar.  CAM is an example of a physiological adaptation.

The forests of the Coastal Redwood (Sequoia sempervirens) are lush, green, and typically receive a generous amount of rainfall during the winter but little rain during the summer. How do the redwoods survive the dry season? While the North Coast doesn't get much rain in the summer, it does have regular fog. Scientists have long suspected that redwood leaves, especially those near the top of the tree, are able to absorb water from fog without adversely affecting photosynthesis. When stomata are covered by even a thin film of water, the water can block the flow of carbon dioxide into the leaf, limiting photosynthesis.

How can redwood trees absorb enough water through their stomata without impairing photosynthesis?  In 2022 Alana Chin, a graduate student at UC Davis, and her colleagues examined numerous leaf shoots from redwoods in various geographic zones and noticed that each tree had two distinct types of redwood shoots. The two shoots had structural adaptations that made them either better suited for absorbing water or better suited for photosynthesizing.  Axial shoots have leaves that are pressed close to the twig, resembling an asparagus stalk. Peripheral shoots have needle-shaped leaves that extend outward from the twig on both sides and are thus exposed to more sunlight.  Leaves on axial shoots can easily trap moisture next to the twig and absorb it at about four times that rate of peripheral shoots. A tall redwood can absorb about 13 gallons of water in the first hour after getting wet. Peripheral shoots are superior at photosynthesis, having densely packed stomata and waxy, water-repellent coatings. Redwoods in drier southern areas have a greater concentration of axial shoots higher in the tree than trees in northern areas. If you have redwood trees planted as landscape trees in your neighborhood, take a look at their axial and peripheral shoots. Learn more about them in this Scientific American article, Redwoods Grow Weird Leaves to Suck Water from Air.

Snow plant (Sarcodes sanguinea) is quite unusual looking. The parts of the plant above ground (its flower stalk and flowers) are completely red; the underground root is white. It has neither leaves nor chlorophyll and cannot photosynthesize. How does it live? Its roots obtain nutrition from underground mycorrhizae, specialized underground fungi composed of strands of cells growing in the soil. Mycorrhizae, in turn, obtain nutrition from roots of the conifer trees growing nearby. For that reason snow plant is always found growing close to conifers.  The conifer trees rely on mycorrhizae to bring them water and minerals. The conifers and the mycorrhizae have a symbiotic relationship, while the snow plant is a parasite on the mycorrhizae. The flower stalk and flowers begin to grow in late spring, when the snow melts. The flower of the snow plant has five petals, which are mostly fused along their edges, resembling a bell. The snow plant's adaptations to its habitat are so specific that it would not be able to exist without mycorrhizae and conifers.

Think about plant adaptations when choosing plants for your garden. Generally speaking, the better a match between a plant's adaptations and the conditions in your garden, the better the plant will perform.  If you choose a plant native to an area that is much different from your garden, you will probably need to make some changes in your garden so it can provide for more of the plant's needs. 

Want to learn more about this topic? Attend our workshop on Adaptations of California Native Plants (Wednesday, May 22), part of the Master Gardeners' 2024 Spring Workshop Series. For information about all the workshops, and to register, visit our website.  All workshops are free, but registration is required.

PLANT SALE!  Mark your calendar for our plant sale on Saturday, May 18, 2024 from 9 am–noon.  The sale will be held at the Master Gardeners Demonstration Garden at Patrick Ranch.  The plants, which are selected to thrive in our climate, have been propagated by UC Master Gardeners of Butte County. For more information and a partial list of the plants that will available, visit our website.

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.