This team of author and photographer direct your attention to the ornamental value of tree bark, in the hope that you will be inspired to use trees more effectively, taking advantage of bark’s many appealing qualities.
Bark’s ornamental qualities are too seldom considered when deciding which trees to include in a garden, yet trees with distinctive bark can contribute a great deal of visual interest to a landscape. Tree bark is significant because trees have such an important presence in the landscape; they take more space and reach higher than other plants, their vertical trunks providing a context for the rest of the garden. Bark has ornamental value in every season of the year; only the foliage of evergreens and the form of a plant contribute as much through the entire year as does bark to the appeal of a garden. The bark of a deciduous tree can be of special importance when foliage and flowers are at their ebb.
Bark offers color, pattern, and textural dimension; some trees possess all three attributes, and many trees have at least two of them. Bark can draw your eye to a tree and help you see its form; I have observed this when people come upon the striking winter bark of a paperbark maple (Acer griseum) for the first time. To build a successful garden, one needs to integrate trees in space and time to achieve the desired beauty.
Tree bark can be one of the many elements brought together to create a rich and colorful garden. Bark can focus your attention on the form of a specimen tree, distract your eye away from something best gone unnoticed, or blend with and accentuate a color theme developed in other plants in the garden. A few trees have a bright red bark color that can grab your attention and pull your eyes away from anything else. Among them are a couple of notable Japanese maple cultivars (Acer palmatum ‘Sango-kaku’ and ‘Beni-kawa’), a red form of striped-bark maple (Acer pennsylvanicum ‘Erythrocladum’), and a selection of the native vine maple (Acer circinatum ‘Pacific Fire’). While their red bark coloring is a constant in the landscape, it is chameleon-like, varying in intensity with the season. The younger wood of all these maples is much more vivid in the winter than in the summer. Trees with bright red bark can be used to echo and highlight shrubs with red winter berries, such as hollies (Ilex), or their own red bark, as on red-twig dogwoods (Cornus stolonifera).
Other red-barked trees, including cherries, madrone, stewartias, and other maples, offer more subdued colors in their bark that blend well and will not stop your eye. The ruddy red tones in the trunks of these trees fluctuate minimally through the seasons. The bark on madrone (Arbutus menzesii) can have, in places, greenish undertones that intensify the impact of the red. In a larger garden with no summer water, the madrone is a wondrous garden tree. Its form, bark, and beautiful foliage are captivating year-round.
The reddish flaking bark of tall stewartia (Stewartia monadelpha) accentuates its elegant form all through the year. It, too, is an outstanding garden plant, with attractive white flowers in summer and colorful fall foliage. Trunks of paperbark cherry (Prunus serrula) have bark that peels in translucent layers; the bark is so captivating that it is used to cover decorative boxes in Japan. It will be noticed in your landscape too. This cherry is susceptible to a fungal disease (brown rot), so best to plant it in a sunny spot with good air circulation.
Green-barked trees blend, rather than contrast, with most of the foliage in a garden. The younger bark on our native vine maple is green, though it becomes gray with age. The bright red and orange fall foliage contrasts nicely with the trunk, as do the red and chartreuse flowers in spring. Most of the striped-bark maples have bark with a background of green highlighted by the light-colored striping that gives them their name. Manchurian striped-bark maple (Acer tegmentosum), in particular, holds the contrasting green and white striping in its bark even as the tree ages. Lacebark pine (Pinus bungeana) has green bark mottled with gray and beige tones. The green in the bark is most apparent in younger trees, but the pattern remains into maturity. This species of pine seems to be happier where summers are warmer than in the Puget Sound Basin. The rare Chinese quince (Pseudocydonia sinensis) is a fine tree, with mottled bark of gray, green, and brown; its fluted trunks are riveting and make it a great choice for use as a small specimen tree.
Birches (Betula) are the most dramatic of white-barked trees for West Coast gardens, and B. utilis var. jacquemontii is the most dramatic of the birches. Its color is so stark and intensely pure that it can be used to alter the perception of spatial depth in a garden. Planted in a group, the trees will seem to foreshorten a space. Other birches, for different reasons, add white to the garden but with a softer effect, leaving spatial perception unaltered. The rosy white peeling bark of Chinese paper birch (Betula albosinensis var. septentrionalis) gives a pale rose warmth to surrounding plantings. The black and white contrast in the bark of European white birch (B. pendula) blends no color and all colors in one trunk, mellowing the starkness of each. The furrowed bark and its diamond- shaped black patterns add to its ornament and draw the eye to the trunk.
A patterned bark draws your eye to a tree and, in particular, to its trunk, pulling your attention into spaces close to the tree. Trees with mottled bark work well to highlight an area in your landscape. They also help to define an intimate space like a patio or sitting area. Persian ironwood (Parrotia persica) has a patchy bark in mingled tones of green, chartreuse, and gray. The mottling develops with age, as the bark begins to exfoliate, and it touches every trunk of this multi-trunked tree. Korean dogwood (Cornus kousa) also develops a mottled bark. When the tree is young, the bark is smooth; in time, the bark begins to exfoliate in small, camouflage-like patches of dark gray, yellow beige, and brown gray.
The crape myrtles (Lagerstroemia) also have beautiful mottled peeling bark, as noted in Paul Bonine’s excellent article in the July 2010 issue of Pacific Horticulture. For the northern portions of the West Coast, the hybrids of L. fauriei are the best performers, as they are more cold tolerant, thrive with good drainage, and are resistant to powdery mildew. In a hot location, they will even bloom regularly. In warm, interior regions of California, the many cultivars of L. indica are an excellent choice for a tree with beautifully patterned bark. Patterning with less texture is found in the striped bark maples mentioned earlier. The white, parallel, more-or-less vertical striations in the bark draw your eye to the form of the tree and lighten a darker space in the garden. Understory plants with large leaves, such as devil’s club (Oplopanax horridus), Diphylleia cymosa, or Chinese mayapple (Podophyllum pleianthum) are all good foils for trunks with patterned bark.
Whether rough or smooth, textured bark on trees can be used to good visual effect and, in the case of peeling bark, to auditory effect. Texture and sonics are offered by such trees as river birch (Betula nigra) and the other birches mentioned earlier, madrone, and the paperbarked maples and cherries; the birches are definitely the noisiest. The rustle of wind through the bark of a specimen of B. utilis var. jacquemontii near our back door is not at all like the rustle of leaves. The sound will pull me from the house into the garden to find out what is making the noise; once outside, of course, I enjoy the garden. Curled and peeling bark, when backlit by the sun, can also illuminate the fringes of the trunk and intensify the bark’s color, presenting a wonderfully fleeting visual moment in the garden.
Some trees develop a thick-ridged bark, especially with age. Douglas-fir (Pseudotsuga menzesii) and ponderosa pine (Pinus ponderosa), both West Coast natives, add rough-textured bark to a garden. Both are also large trees. A selection of Japanese maple (Acer palmatum ‘Pine Bark’) develops a rough, pine-like bark, yet remains under thirty feet in height. Both Eastern dogwood (Cornus florida) and common persimmon (Diospyros virginiana) have rough bark, though more blocky than ridged, adding a distinctly different texture from that of our native conifers.
A softer texture is characteristic of the mottled flaky bark of mature zelkovas (Zelkova serrata). The young grayish bark is marked with lenticels that disappear as the bark begins to exfoliate, creating a shaggy texture of gray, peach, and orange. Smooth bark provides an important textural contrast in the garden, but can only be appreciated while a tree is young, for it usually disappears with age—even in trees noted for smooth bark, such as Southern magnolia (Magnolia grandiflora) and silk tree (Albizzia julibrissin).
Texture is probably the most overlooked attribute in the skins of the living sculptures we call trees. But even the more obvious possibilities within the realms of color and pattern often go unconsidered. The exceptional gardener—willing to take the time to touch, look, and listen—will find enriching possibilities in extraordinary bark that can harmonize, contrast, dazzle, and surprise.