Hansen's Northwest Native Plant Database

Thuja plicata (Western Redcedar, Giant Arborvitae)




 Plantae – Plants



 Tracheobionta – Vascular plants



 Spermatophyta – Seed plants



 Coniferophyta – Conifers









 Cupressaceae – Cypress family



 Thuja L. – arborvitae



Thuja plicata Donn ex D. Don – western redcedar 

Note: Throughout the years I've written short articles for our website's home pages (home pages are the front page of a website) about these plants. They are now included at the bottom of this page, and are illustrated by botanical drawings and paintings, some of which are from books published from 1500 - 1900.

Plant Brief: This is a magnificent cedar, much revered by the northwest Native peoples. Such was their respect and dependence on this tree that it was called “tree of life.”

Western Redcedar is found on the coast from southern Alaska to northern California and also in the Rocky mountains from Alberta to Idaho and Montana (USDA zones 3b-9). In the north it is restricted to lower elevations (under 1,000’).

Western Redcedar grows rapidly, reaching 180’ and develops massive, tapered boles and a broad, triangular shape – highly ornamental. The branches droop down but turn up at the ends. Both the wood and foliage are highly fragrant. This versatile species prefers moist soil but is extremely adaptable. Can stand in some water in the winter. Shearing can produce hedges which are particularly useful as windbreaks.

The following article was written by Jennifer Bosvert

Description: One of the native giants of the Pacific climax forest, this majestic evergreen also adapts well for use in the garden. In the wild, one might run across the Western Redcedar in boggy, lowland forests, or in the Douglas Fir (Pseudotsuga menziesii var. menziesii) and Mountain Hemlock (Tsuga mertensiana) forests of the mountains.

Among older trees Western Redcedar is obvious and startlingly green, because unlike its fir and hemlock peers, Western Redcedar retains lower branches as it gets larger. Thus in a forest of magnificent brown tree trunks, Western Redcedar is an oasis of green for the eye.

Drooping branches that flare out near the ends are adorned with lacy scale-like leaves. Fanning out in thick green swathes, the scale-like tendrils create a gradating pattern of color as light hits the narrowly conical tree.

Although the giants of this species reach 200’ and 1,000 years of age on the Olympic Peninsula of western Washington, they work beautifully in the garden. Not a true cedar (hence “red cedar”), this species grows to a maximum of 130’-200’ at maturity with a trunk diameter of up to 10.’ In old growth forests, one can observe the enormous buttressed base of the mature trees that spread out much broader than 10.’

Depending on exposure and the age of the tree, the bark appears from its natural red color to a more weathered gray. The bark easily shreds off into soft reddish fibers and grows thin, unlike the thick bark of its forest cousin, the Douglas fir. Pressed closely to the twig, the 1.5-3 mm long leaves are green above, and show an identifying white “butterfly” or “bow-tie” underneath where they come together in a regular, repeating pattern.

Male and female flowers are found on the same tree although usually on separate branches. The male cones appear small and reddish, and unlike the other native “cedars,” the half-inch long female cones grow upright and bent back along the branch. The young green cones resemble the bowl of a pipe and turn bluish then ripen red-brown as they open into a small woody rosette. Ten to twelve scales per cone is average, although usually only about six are fertile and bear seed.

When walking nearby, the spicy, sweet smell of the Western Redcedar is distinctly different from the other smells of the northwest forest and very pleasant. This tree grows quickly, sometimes up to one meter per year, however a tree of this species will need hundreds of years to achieve the maximum size discussed above.

Mature Thuja plicata on Reed College Campus, Portland, Oregon

Habitat and Range: Thuja plicata is found from Alaska to northern California, and from the Pacific Ocean to Montana. It prefers the maritime climate of the coastal fog belt, but is found also on dryer slopes, naturally occurring along the Pacific Ocean from the Alaskan panhandle through British Columbia, Washington, Oregon and just barely into northern California. In the interior, Western Redcedar is found throughout the Cascades, and in the wetter parts of the Rockies in British Columbia, northwestern Montana, northern Idaho and northeastern Washington. In other regions of eastern Washington and Oregon, Thuja plicata is restricted to pockets in wet ravines and valleys. Western Redcedar grows in a variety of soil types and does very well in boggy areas.

Ornamental Values: While the mature size of the Western Redcedar might seem intimidating, it has versatile garden uses. It's use as a vibrant tree is obvious in the yard, garden or park, but young trees can also be planted and maintained as a hedge. The lacy foliage interweaves between the individual plants and can be sheared or the terminal leaders topped to make a graceful screen or hedge. Unlike other conifers, red cedar sprouts new foliage along the trunk, making it an even more attractive hedge specimen.

Western Redcedar is hardy to USDA zone 4. As mentioned above, Thuja plicata is happiest in the coastal fog belt, however it grows well in drier soils, especially those a little richer. It can tolerate waterlogged soils, heavy clay and also shade (with nutrients), but does not tolerate salt spray. Generally it does well in a climate of cool summers and wet, mild winters. Growing at rates of up to one meter per year, Western Redcedar can make a quick impact on the yard or garden.

Native Plant Gardening/Wildlife Habitat: Western Redcedar offers excellent cover from predators for birds and squirrels. Birds, like Towhees or Juncos, appreciate the cover provided by the persistent lower limbs, and hummingbirds like to visit the new growth buds in the spring. Like most conifers, the primary wildlife value of the Western Redcedar is found as winter shelter, cover from predators, and as a nesting site in the spring.

Restoration and Mitigation Values: Western Redcedars love to have their feet wet, and therefore are an obvious choice for streamside and wetland restoration. Although shallow rooted, this tree thrives where most conifers will not grow. Seedlings and young trees transplant well and grow quickly which is especially helpful with habitat stabilization.

Historical and Cultural Uses: Called “the tree of life” by the Kwakwaka’wakw of the central coast of British Columbia, this tree surely lives up to that name.

The myriad uses are too many to name them all. Some of the more famous uses include the construction of canoes (hence “canoe cedar”), lodges and totem poles.

Lodges were usually about 20’ wide and 40’ long, and the cedar boards used to construct them were about 2” thick and 2’-5’ wide. The wood was split in planks from living trees, using antler and wedges made from a yew tree, and then the lodge timber construction was held together with rope made from cedar bark.

The Western Redcedar canoes were such amazing vessels that about 1900, J.C. Voss bought an average 38’ dugout red cedar canoe from Vancouver Island Indians, and with the addition of 3 masts and a cabin, he used it to sail around the world.

Native Americans also used the fiber of the bark to make clothes, raingear, mats, ropes, and was so soft that it was used in baby diapers. The smaller, younger roots, and narrow withes were used in basketry and to make fishing nets and traps. Other various uses include: wood for arrow and spear shafts, bark fibers for tinder and wicks, wood for ceremonial carving, rattles and toilet sticks (prior to the introduction of paper), and the low smoke, aromatic fire from red cedar was favored for smoking salmon. It should also be mentioned that Thuja plicata is the official tree of British Columbia. Up until 1900, one could still see the stumps near Orofino Idaho, of the Western Redcedars that the Lewis and Clark expedition felled to make their canoes for the western half of the Corps of Discovery.

Edible and Medicinal Uses: Reportedly, Native Americans eat the spring cambium of Thuja plicata fresh, or they dry it for eating later. The pitch is chewed like gum, and as mentioned above, the wood of Western Redcedar is favored for smoking salmon.

Various infusions and decoctions of the bark and twigs of Western Redcedar were used historically by Native Americans to treat several ailments, including: rheumatism, lung ailments, colds, fevers, and stomach ailments.

NOTE: Please use caution when preparing or eating any parts of a plant. Identification of the species and knowledge of a plant’s toxicity are both essential before using any plant species medicinally or otherwise. Please consult with a health professional before attempting to treat any ailment.

Propagation Techniques: In the wild, one can observe new red cedar trees sprouting readily from fallen trunks and branches of nurse trees (along with the requisite huckleberry of course). However, for those of us without a nurse log in our backyard:

Seeds – Collect the cones from trees after they have turned from yellow to brown, but before they open. Then dry on a plastic sheet for several days until the cones dry and open. Shake the seeds loose from the cones, and separate the seeds from the chaff with a light fanning. Do not de-wing the seeds. The seeds germinate well without stratification, however a cold moist stratification at low temperatures can stimulate faster germination of stored seeds. In the spring sow at a depth of 0.5 cm in moist soil. Shade for the first year.

Photo by Walter Siegmund:

"This is the 'Hobbit Tree,' the largest known Western Redcedar in the world. It lives near the northwest shore of Quinault Lake north of Aberdeen Washington which is about 21 miles from the Pacific Ocean, near Higley Creek in the southwest corner of Olympic National Park."

Cuttings – Layering and cuttings work well. Cuttings taken of half-ripe wood in late summer will root in a shaded cold frame by September (and should winter over in the frame).

Common Diseases: Thuja plicata is relatively disease free. The primary risks to Western Redcedar are trunk and root butt rots, however these generally affect only old trees. The acidity of the bark keeps it free of moss, lichens or fungi. Although not strictly a disease, young trees should be protected from browsing by deer.

See Identification of False Cedars for more information.

From Homepage March 12, 2004

Western Red Cedar (Thuja plicata) is one of our most versatile northwest native trees. The forest green foliage stays year-round and smells fresh and clean. If you need a fast growing hedge, this is the perfect choice. You can sheer it back for a neat looking living wall, you can let it grow high to make an excellent sound barrier. Planted alone, the tidy conical shape makes an unmatched architectural statement.

Also known as Giant Arborvitae, this tree grows in many climates and is about the only cedar that can tolerate wet feet in the winter months. And it grows FAST. Northwest Native Americans call this tree the "Tree of Life."

Whether you want a hedge, a background for smaller plants or a specimen tree, Western Red Cedar could be just the thing for your landscape.

From Homepage September 2, 2005

This week we focus on the Western Red Cedar (Thuja plicata). This is an important tree in our culture, in the history of our land and was an element the First Nations relied on for all phases of their existence.

Interestingly, few cedars were cut down before explorers from other lands came to call. Instead of felling the trees, fallen logs or boards split from living trees were used.

In their 1994 book, Plants of the Pacific Northwest Coast, Pojar and Mackinnon say:

"The power of the Red cedar tree was said to be so strong a person could receive strength by standing with his or her back to the tree...It is called the 'tree of life' .... and is still held with highest respect by all northwest coast peoples for its healing and spiritual powers."

Western Red Cedar is often used as a living fence in the landscape or as a striking specimen tree. Especially successful plants beneath your Western Red Cedar are Sword Fern (Polystichum munitum), Western Trillium (Trillium ovatum), False Lily-of-the-Valley (Maianthemum dilatatum) and Stream Violet (Viola glabella).

Because this tree does not have needles, it is kinder to a fastidious gardener. It has a uniquely clean and fresh aroma.

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