By Jeff Oster, UC Butte County Master Gardener, October 13, 2017.

Chico's Lindo Channel, also known as Sandy Gulch, is a seasonal waterway that serves as a flood control channel.  The soil has significant percentages of sand and cobble, further enhancing summer dryness. Since moving there in 1991, I have established a drip irrigation system to help establish native plants on the streamside bank on my property.  What has worked for me along the Channel could also work in a variety of gardening conditions.

I have separated the plants according to size (and therefore purpose), forming three articles: today's article on large trees, and two more articles, one smaller shrub-trees, and another on shrubs, which will appear in this column in the coming weeks.  Each article will describe plants that have been successful in the Lindo Channel gardening conditions, and indicate the variety of insects, birds, and mammals that make their homes in them.

Large Trees

Large trees are highly effective features in a landscape, but are also useful in creating a high canopy so that a variety of plants (including shade plants) can grow underneath, and in providing substantial habitat for wildlife.  Western Sycamore, Oregon Ash, Big Leaf Maple, and Valley Oak do well in the Lindo Channel environment.

Western Sycamore (Platanus racemosa)

Western Sycamore (also commonly known as California sycamore, California plane, and Aliso) is native to California and Baja California, where it grows in canyons, floodplains, and along streams. They are also often found next to drier habitats such as chaparral, valley grassland, mixed woodlands or evergreen forests.

Because their roots go down, not out, if given enough water, they are good trees near patios or in urban environments. They grow quickly (up to 30 feet in five years). Eventual height can reach 115 feet, but more commonly 65-85 feet, with a trunk diameter up to three feet. The trunk generally divides into two or more large trunks, each splitting into many branches. The bark is multi-colored, with splashes of white, pinkish gray and pale tan. The older bark becomes darker and peels away. Leaves are up to 10 inches wide. After a good rain, the leaves produce a fresh, earthy scent. Western Sycamore trees are deciduous, with leaves turning yellow and orange-brown in the fall. Flowers are one-inch spheres that become seed balls. Western Sycamores are tough and easy to grow: they will tolerate a wide variety of soils and pH levels and prefer full sun, but they do need a lot of water. Western Sycamores are important hosts for Western Tiger Swallowtail and other butterflies, hummingbirds, finches, waxwings, and pine siskins. Hummingbirds use the down from stems and leaves to line their nests. They are deer resistant trees, but are susceptible to anthracnose fungus (leaf blight) if it rains when leaves are expanding. The disease causes disfiguration of the leaves in mild cases and leaf loss in severe cases

For more information on Western Sycamore, see California Native Plant Society, Western Sycamore.

Oregon Ash (Fraxinus latifolia)

Oregon Ash is found from the southern coast of British Columbia, west of the Cascades in Washington and Oregon, to the coast ranges and Sierra Nevada range of California. It grows quickly to 75 feet in height. Long-lived, easy to care for, this tree likes moist to wet soils, including heavy soils near streams, lakes and in flood plains, in sun to partial shade. It also grows on sandy, rocky, and gravelly soils in riparian areas (near river banks) or areas with seasonal flooding. Foliage turns bright yellow in fall.

Seeds are single samaras (fibrous wings of papery tissue), with long wings (up to two inches) borne in large, drooping clusters on female trees. These are eaten by birds and small mammals, while the foliage provides sustenance for the larvae of pale swallowtail, two-tailed swallowtail, and western tiger swallowtail butterflies.

Oregon Ash trees are susceptible to caterpillars and scales, anthracnose, root rot, rust, sooty mold and verticillium wilt.

For more information on Oregon Ash, see California Native Plant Society, Oregon Ash.

Big Leaf Maple (Acer macrophyllum)

Big Leaf Maples are native to western North America, mostly near the Pacific coast, from southernmost Alaska to southern California, and also thrive inland in the foothills of the Sierra Nevada mountains. They are found in riparian areas in hardwood forests and dispersed through relatively open canopies of conifers, mixed evergreens, or oaks. Growth is very fast at first, to 50 to 65 feet, eventually reaching up to 160 feet in height with a trunk diameter of 12 to 36 inches. The 4 to 6-inch clusters of greenish-yellow flowers appear with leaves in the spring. Leaves are six to twelve inches across. In fall, they turn gold to orange-yellow. Trees are long-lived. These are good native trees near lawns; they need lots of water for the first year or so. They are not as tolerant of wet soils as ash trees and can be drought tolerant in their native range. Tolerant of soils with serpentine and clay; will survive (though not at best) in sandy soil.

The seeds, buds and flowers of Big Leaf Maple are a favorite food of many small mammals and birds. Speciesassociated with Big Leaf Maple are evening and blackheaded grosbeaks, goldfinches, pine siskins, warblers, vireos, bushtits and kinglets.

For more information on Big Leaf Maple, see California Native Plant Society, Big-Leaf-Maple.

Valley Oak Quercus lobate

The Valley Oak is native to riparian areas of the central valley, the valleys of the Sierra foothills, and the coast ranges of California. The fastest growing (three to four feet per year) of California oaks, it is deciduous and can grow to 70 feet. With age, the branches are irregular and spreading. Leaves are deeply lobed. Valley oaks like sun and moderate water with a water table above 70 feet. Do not water established oaks. They are long-lived and tolerant of seasonal flooding and a variety of soils (though they prefer deep soils with pH of 6 to 8).  These trees are deer resistant.

Valley Oaks provide nesting sites for birds, and are popular with insects year-round and with the birds that eat them (including bluebirds, warblers, phoebes, flycatchers, vireos, swallows, and titmice). This tree hosts numerous species of butterfly, including California sister, propertius duskywing, mournful duskywing, golden hairstreak, and gold Hunter's hairstreak.  The acorns of the Valley Oak are a staple food of the acorn woodpecker, but a variety of mammals and birds also eat them, including scrub jays, yellow-billed magpie, deer, bears, and squirrels.

For more information on Valley Oak, see: California Native Plant Society, Valley Oak.

The following two charts refer to plants referenced in the three part series on native plants that thrive in Chico and Lindo Channel.

Channel Native Plant Characteristics

Channel Natives Flowering Time and Color