Tree Profiles Western Red Cedar

The Western Redcedar, thuja plicata, is also called the giant arborvitae, the giant tree of life. The name is properly spelled Redcedar, not Red Cedar, to signal that the tree is not a true cedar. A member of the tough and resinous cypress family, this evergreen can grow to 200 feet high or more, and live for several hundred years.

The range of the Western Redcedar runs from southeast Alaska through British Columbia, Washington, and Oregon to California’s north coast. A separate population of the species grows in parts of Idaho, Montana, and British Columbia.

Western Redcedar trees are best adapted to cool damp conditions, and sometimes grow in swampy ground. They frequently stand on riverbanks or facing the open ocean, making harvest of this valuable tree all too easy. Relatively temperate winters suit them, as do cool wet summers. They thrive in the Coast Ranges, especially in the Olympic Peninsula and on the west slopes of the Cascade Mountains, though they are found in the Rocky Mountains as well.

The trunk of the Western Redcedar is straight and tapered, but is set on a thick, irregularly fluted platform that often catches soil in its furrows and grows seedling hemlocks, cedars, or ferns, creating a hanging garden.

The thin red-brown bark of the Western Redcedar is fibrous and shreds readily; northwestern American Indian tribes wove it into blankets, cloaks, and other items of use and beauty.

The fragrant foliage of the Redcedar is a shiny dark green tinged with yellow. The ferny branches are composed of scales that grow in flat shingled fans on jointed twigs. The species name thuja plicata comes from Greek words for “fragrant wood” and “braided,” probably referring to the plaited look of the leaf scales, according to the U.S. Forest Service.

The trees stand out against the dark needles of the hemlock and the brown bud tipped branches of the Douglas fir that share the range. Western Redcedar cones are half an inch long or less, and appear in clusters.

The wood of the Western Redcedar is permeated with resin than makes it extremely durable, even in contact with wet earth. When first cut, Redcedar lumber is very aromatic. The heartwood is pinkish to reddish brown, while the sapwood is nearly white. The straight-grained wood shrinks very little in drying.

The Haida, Timshian, Tlingit, and several other tribes made totem poles out of the trunks. They also used lumber hand-milled from the tree in constructing houses, which they roofed with shredded bark. Huge ceremonial canoes were carved from single trunks.

The modern construction industry uses the rot-resistant wood for shakes, shingles, and siding. However, since the resinous wood is very flammable, many jurisdictions now restrict its use in housing. It is still widely used for long-lasting fence posts and poles, as well as in boat building.

The Western Redcedar is a beautiful and useful tree. It is valuable in construction, especially for its resistance to decay, but perhaps even more valuable for its part in the ecology of the temperate rain forest.

Other sources:

Conifers of California, by Ronald M. Lanner

The Audubon Society Field Guide to North American Trees-Western Region, by Elbert L. Little

North American Wildlife; Trees and Nonflowering Plants,  eds. Edward S. Barnard & Sharon Fass Yates