Prickly thickets of California wild rose, Rosa californica, are not often much to look at, even while adorned with small and sparse pink roses in spring and summer. The fragrant flowers can actually range in color from white to rich pink, and may have more petals, but are not abundant enough to be very impressive at any one time. In autumn though, all the flowers that bloomed in the previous few months leave bright orange or red fruiting structures known as ‘hips’, that linger on the bare canes through winter.
The rose hips of California wild roses had historically been used to make herbal tea because they contain so much vitamin C and have a pleasant flavor. (California wild rose is a ‘tea’ rose but not a hybrid ‘T’ rose.) They can also be made into jelly or sauce. The only problem is that birds like them too, so often take them before anyone else has a chance to.
The most common of a few species of cottonwood that are native to California seems as if it should not be. Populus deltoides is the Eastern cottonwood. This name implies that it should be native primarily to regions of the East. Yet, it naturally inhabits every American State except for Hawaii and Alaska. Since it is so familiar locally, it is simply cottonwood.
It grows wild in riparian ecosystems, and occasionally sneaks into adjacent landscapes. It is almost never an intentional acquisition. Cottonwood grows too aggressively and too large for refined home gardens. It works better as a grand shade tree for parks and urban waterway trails. As a riparian species, it requires either riparian ecosystems or irrigation.
Mature cottonwood trees may be almost a hundred feet tall, and rather broad if exposed. Their bark is handsomely furrowed. Yellow autumn color of the deciduous foliage can be surprisingly vibrant within arid climates, or if rain is later than frost. Vigorous trees can be susceptible to spontaneous limb failure, so may occasionally justify aggressive pruning. Roots might be voracious.
During the summer, the native white alder, Alnus rhombifolia, is a nice shade tree that looks bigger than it really is. By late winter, the bare deciduous canopy has an appealingly picturesque silhouette. This time of year is actually when white alder is typically less appealing, with dead foliage that provides no interesting fall color, but lingers until knocked down by rain or late frost. Yet, even now, it sometimes surprises with these funny looking floral structures that are interesting both in the early winter landscape, and with cut flowers.
In past decades, white alder was an ´expendable’ tree that was put into landscapes for quick gratification while slower but more desirable trees matured. By the time the desirable trees matured, the alders were removed to make more space for the desirables. This technique was practical because, like many fast growing trees, alders do not live very long, so start to deteriorate after about twenty five years anyway. However, alders often live longer than expected.
Mature alders are usually less than fifty feet tall where they are well exposed. They can get at least twice as tall where shaded by other trees or big buildings. Their plump trunks with mostly smooth silvery gray bark make them seem larger than they really are though. Too much water promotes buttressed roots which can displace pavement.
‘Foggy Oak Morning’ by Karen Asherah, is another example of the local scenery that I miss while not taking a bus or walking. I drove past this scene for years on my way to work outside of San Martin without ever bothering to take a look at it. This happy tree is a native valley oak, Quercus lobata, like those that had been common throughout the Santa Clara Valley until only about two centuries ago. It is not exactly the sort of shade tree that everyone wants in a compact suburban garden, but is grand enough for large spaces like parks.
Mature specimens may not seem to get as tall as oaks in the Appalachian Mountains, but are actually the largest oaks in North America, and live more than five centuries. The tallest trees are mostly less than seventy feet tall, but can get taller. Trunks of the oldest trees are commonly six feet wide or wider. The distinctively and uniformly furrowed bark is as classically ‘oakish’ as the rounded prominent lobes of the deciduous leaves, and the sculpturally irregular branch structure. Odd stem galls, commonly known as ‘oak apples’, are home to the larvae of tiny wasps that rely on valley oaks for everything they need. Incidentally, Paso Robles, or ‘El Paso de los Robles’ is named for the valley oaks in the area, which Spanish immigrants thought resembled the ‘robles’, the European oaks that inhabit Spain.
More information about ‘Foggy Oak Morning’ can be found at the website of Karen Asherah at karenasherah.com.
Since it is native to coastal chaparral between Monterey and the middle of the Baja California Peninsula, holly leaf cherry, Prunus ilicifolia, is right at home in local gardens of the central and south coasts. Although it can be a nice refined hedge if not shorn too frequently, it is better where it has space to grow wild into a mounding shrub, and can eventually grow into an undemanding informal screen as high and broad as fifteen feet. Width is easier to limit with selective pruning than with shearing. Besides, unshorn plants bloom with clusters of minute white flowers in spring, and produce interesting deep red or purplish red cherries in autumn. Unfortunately, the cherries have very big pits with only minimal sweet pulp. The small glossy leaves have somewhat bristly teeth almost like those of some hollies.
Though native mostly to the Sierra Nevada and Coast Ranges between San Francisco and Oregon, California black oak, Quercus kelloggii, also inhabits isolated colonies in lower mountains as far north as the southern half of the Oregon Coast, and as far south as San Diego County. It actually occupies more area than any other hardwood tree in California. Wild trees competing in forests can get more than a hundred feet tall and live for five centuries. Well exposed urban trees may take their first century to eventually get about half as tall with trunks as wide as four feet.
Even while young, California black oak is a distinguished tree, with a broadly rounded canopy and elegantly arching limbs. The smooth silvery bark of young trees eventually becomes dark and uniformly checked with maturity. The distinctive deeply lobed leaves are about five inches long, and turn gold, soft orange or even brownish red before falling in autumn.
There is no way to say it delicately. Flannel bush, Fremontodendron californicum, is not easy to work with. It grows rapidly and rampantly with awkward form to about ten feet high and broad, but then starts to deteriorate when only about twelve years old. It can deteriorate even sooner if well irrigated. The fuzz on the foliage and young stems is irritating to the skin, especially during warm weather, so is very uncomfortable to handle. Otherwise, for out of the way spots, flannel bush is a striking native plant with impressively abundant bright golden yellow bloom this time of year. Neglected plants that do not get pruned or watered seem to be happier and more colorful, and can get older and much larger.
New spring foliage will soon be obscuring the rusty red or light yellow stems of osier dogwood, Cornus sericea (or Cornus stolonifera). Because this odd dogwood is grown for these distinctively colorful stems instead of blooms, it can be pruned harshly before foliation, to promote more twiggy growth for next winter. Unpruned plants form thickets five to ten feet high and ten or more feet broad. The flowers are actually rather pathetic relative to those of other dogwoods, since they lack colorful bracts. Where exposed to frost, the opposing two or three inch long and one or two inch wide leaves can provide nice reddish autumn color.
There was a theme when I assembled these six pictures. I just can not remember what it was now. I am very happy with the three species from Del Norte County, #3, #4 and #5. #6 is my favorite though. It was so unfortunately necessary to remove the venerable old trees. It was necessary to remove their suckers too. I combined the two unpleasant tasks in a rather satisfying manner. There was absolutely no indications that the original trees were grafted. I looked for unions. I was informed that the suckers were visually identical to the original trees. I hope that the suckers that I transplanted within the centers of the decayed trunks will grow into trees that are new copies of the original trees!
From Santa Barbara to Vancouver, and also in central Idaho, the humble native coral bells, Heuchera micrantha, is not much to look at, with compact rosettes of relatively small and bronzy rounded leaves with weird tomentum (hairs). In spring and early summer, and sometimes again in autumn, sparse trusses of minute brick red flowers hover about a foot above on wiry and slightly fuzzy stems. Old plants that get bare in the middle can be divided into several small plants in spring or autumn.
Modern cultivars are considerably more interesting, with more substantial foliage in various shades of green, gold, tan, brown, bronze and purplish bronze. The larger and variably lobed leaves can be two inches wide or slightly wider. The flowers stand as much as two feet high, but lack color. Most are pale greenish white. ‘Palace Purple’ has deep bronze or almost purplish foliage. ‘Ruffles’ has deeply lobed and ruffled green leaves. Unlike undemanding wild plants that can grow in cracks in exposed stone, modern cultivars like rich soil. Harsh exposure can scorch foliage, so a bit of partial shade is preferred.