Brilliant fall color in maritime Northwest gardens
Many of us are transplanted into our Northwest gardens from the Eastern or Midwestern United States, and nostalgia strikes in October. Fall leaf color, that brilliant glowing finale to summer, glazed the Appalachian hills during my time in Vermont and Virginia. In hopes of recreating some of the glow, gardeners building new memories here can select trees and shrubs that gleam with reds, rose, yellows, and gold in October.
Leaves turn in response to the slowing of the plant's growth, usually observed on deciduous plants native to temperate areas of the world. Green leaves are colored by chlorophyll, the light-capturing pigment that converts light into food for the plant through photosynthesis. As the plant moves into dormancy with cooler temperatures and lower light levels, the chlorophyll production slows and ultimately ceases. The loss of green pigment reveals the hues of other chemical compounds present in the leaves, yielding red, violet, purple, orange, red, and brown, depending on the particular chemical. So deciduous autumn leaf color is, ultimately, a sign of senescence in the individual leaves.
Since observing these changes is a grand autumn experience for many gardeners, which trees and shrubs adapted here will capture the most autumn brilliance? Start by looking at nursery plants. Choose plants for fall color when the leaf tone pleases you. Plants vary in their genetic composition, and two trees of exact same name will not necessarily be equivalently brilliant. Pick it out in color. And when choosing a planting site, look for a place with the most possible late-summer sun, since shady conditions will diminish the color.
Small trees and shrubs offer distinct choices for the selective gardener. Many gardeners think first of the Japanese maples, with their lacy leaf patterns and colors in fall. Two of the most brilliant are Acer japonicum "Aconitifolium" and Acer palmatum "Osakazuki." These maples are familiar to Northwest gardens, but many other trees are not. Look for the Franklin tree, Frankflinia alatamaha, a native American with stunning white camellia-like flowers in late summer, fall foliate in oranges and deep burgundy, and winter bark that peels to reveal a shining trunk. The Franklin tree was found once in the wild in the 18th century, disappeared around 1800, and since has persisted only in cultivation. It's a choice, elegant garden tree beautiful year-round, and grows slowly to about 20 feet.
Another American native, the Serviceberry or Juneberry, Amelanchier sp. (various species are available), grows multitrunked like a shrub, with early spring graceful white flowers. For attracting birds to a garden, this shrub's a winner, with small blue summer fruit attractive to many birds. Fall leaf color is red to orange. Another shrub with good red to orange color is redvein enkianthus, Enkianthus campanulatus. This one also adds light pink bell-shaped spring flowers in early spring.
Thinking of the autumn season as a celebration of plants may help reduce the dismay many gardeners feel at the coming of dark days and set conditions. Begin to observe the subtle and emerging colors on perennials such as peony and edibles like blueberries. Plant a brilliant sumac for texture and interest, with several species of sumac sold in nurseries.
The smooth sumac, Rhus glabra, is a 6 foot or taller shrub with interesting leaf patterns and screeching red autumn tones. The Northwest garden can flare out in fall rather than fading out.
And how can you learn more about gardening? Washington State Cooperative Extension offers several services to King County gardeners. A trained group of gardeners, the Master Gardener volunteers, staff a phone fine at 206-296-3440 Monday through Friday, 10 a.m. to 4 p.m., answering questions and exchanging ideas with callers year-round. King County Master Gardeners also work at local community clinics during summer months; there are several year-round clinics including one at the Center for Urban Horticulture, University of Washington, Monday evenings, 4 p.m. to 7:45 p.m. To get a clinic schedule, call 206-296-3900. Finally, DialExtension tapes offer free access to over 200 short gardening tapes; dial 206-296-3425 to get a listing of tapes.
WSU also offers dozens of gardening bulletins. Some of the material in this article was drawn from Fall Color of Landscape Plants, by Dr. Ray Maleike. These bulletins are available to the public by calling 206-296-3900 for a catalog. Gardening is more enjoyable when mysteries don't have to remain puzzling!
Finally, remember in the press of garden work and chores to stop long enough for appreciation of the beauty and productivity of plants!
Visit WSU's Agriculture Site on the World-Wide Web at http://www.cahe.wsu.edu.