Tree of the Month, July 2023

Arborvitae, American Arborvitae, Northern White Cedar, Eastern White Cedar

Thuja occidentalis

by Martin (Mort) Schmidt for Simply Living

Arborvitae on limestone outcrop in Scioto County, Ohio. Photo by Mort Schmidt.

You have, I have, we all have Arborvitae deep within us. Read on…..

Arborvitae, the Tree of Life, is a tree of paradoxes. Both revered and reviled over history, Northern White Cedar is not a cedar. Thuja occidentalis and its western relative, T. plicata (Western Red Cedar, famously used by the Natives to build totem poles, canoes, and countless other things) are in the cypress family. True cedars are Old World trees. Additionally, Arborvitae’s common names, Northern White Cedar and Eastern White Cedar are appropriate for a tree native to the northeastern US, but the Latin name, T. occidentalis means “Thuja, western”, because it’s from the western hemisphere. 

Range map of Thuja occidentalis. Image from U.S. Geological Survey, public domain. 

Such is the problem with common names. I’ll ask for American Arborvitae at the nursery and White Cedar at the lumber yard. “Thuja” is derived from a Greek word for sacrifice, since its aromatic scent made Arborvitae’s Eurasian relative, the preferred fuel for burnt offerings. 

Like most familiar conifers, Arborvitae is an evergreen. But its foliage does not resemble needles like those of pine, spruce, or fir. Its foliage consists of scaly leaves arranged in fan-like branches. 

American Arborvitae foliage and cones. Photos by Mort Schmidt.

The bark is dark, reddish brown, and comes off in long, narrow strips. The small cones are approximately half an inch long. Arborvitae is generally easy to recognize by its flat foliage, but it’s easily confused with its Eurasian cousin, Thuja orientalis, which is sometimes used in landscaping, and also called “Arborvitae”. The varieties of Arborvitae used for landscaping are often shrubs, and no more than 15 or 20 feet tall. Arborvitae requires little maintenance and its dense foliage provides a lot of privacy, which explains its widespread use in landscaping. But many feel they’re overused, which is why Arborvitae is also widely disliked. 

The elongated female seed cones are approximately ¼” to ½” long. Atlantic White Cedar (Chamaecyparis thyoides, also not a cedar), has similar foliage, but can be distinguished by its ¼” spherical cones and its less-flattened foliage. Arborvitae is monoecious, having male pollen cones and female seed cones on the same tree. 

Arborvitae does well in rocky limestone terrains, and is fairly common in southwestern Ohio. It also thrives in wet soil, and is therefore the “Cedar” for which Cedar Bog, south of Urbana, Ohio is named. (Cedar Bog isn’t a bog either, it’s a fen. Just sayin’). Northern White ‘Cedar’ grows so vigorously that a fallen tree sometimes sends up shoots at various points, resulting in trees growing in a straight line, according to John Bates and April Lehman’s Trailside Botany, 101 Favorite Trees, Shrubs, & Wildflowers of the Upper Midwest. Arborvitae is the longest-lived tree in eastern North America, according to Wikipedia and other sources. One specimen is at least 1,653 years old. 

Northern White Cedar is a significant lumber tree. The common name, “Cedar” was applied because the wood is soft, lightweight, rot-resistant, and aromatic. T. occidentalis lumber has a Janka hardness of 320 lbf and a density of 0.35 g/cc, according to the Wood Database.  This makes it the lightest and softest wood on my list of 68 Ohio trees, which has a median hardness and density of 1,010 lbf and 0.61 g/cc, respectively.

Lumber applications are limited by Arborvitae’s softness and relatively small size, but its high durability (rot resistance) and moderate cost make it well suited for fences, posts, shingles, outdoor furniture, and log cabins. Like many of the softer woods, Arborvitae is also used for paper pulp. The Indians used Arborvitae extensively for canoe frames, since it’s light-weight and rot resistant. Arborvitae is one of the most widely-planted trees for landscaping, and it’s often claimed to be the first New-World tree to be planted in Europe. 

Arborvitae is valued for its dense foliage, which offers privacy and noise reduction. Photo by Mort Schmidt. 

Arborvitae foliage is favored food for deer, and the trees often lack greenery in the lower few feet above ground level – the so-called browse line. Rabbits also consume Arborvitae foliage, while birds and squirrels eat the seeds. 

The Native American Ethnobotany Database lists numerous medicinal applications for Arborvitae, including: 

Abnaki – Poultice of powdered leaves applied to swellings. 

Algonquin – Decoction of branches taken for rheumatism. Branches used in the steambath for colds. Branches used in the steambath for fevers. Infusion of plant taken for menstrual disorders. 

Chippewa – Compound containing charcoal pricked into temples with needles for headache. Twigs burned as a disinfectant to fumigate a house for smallpox.

Cree – Decoction of needle-covered branches or juice taken for urine retention or sore bladder. 

Iroquois – Decoction of plant tips used as a foot bath for rheumatism. Decoction used as a wash or poultice applied to cuts, bruises and sores. Fermented compound decoction taken for fever. Infusion of leaves taken by women as a tonic and diaphoretic to increase the milk flow. Fermented compound decoction taken when a ‘person is tired.’ Branches used in closets to prevent moths.

Malecite – Dried inner bark pounded, mixed with grease and used for burns. Gum used to fill cavities and for tooth pain. 

Alice Thomas Vitale’s Leaves in Myth, Magic, and Medicine indicates that the Indians used Arborvitae boiled in bear grease as a salve for the treatment of skin conditions. A tea made from the leaves was imbibed to treat headaches, coughs, gout, and fevers. The smoke of burning leaves was used to revive the unconscious and to ward off evil spirits. Vitale also lists insect repellents, soaps, room deodorizer, and perfumes as present-day products that incorporate extracts of T. occidentalis

“Oil of Cedar” is widely touted on websites as a remedy for various conditions. While it might well have beneficial properties, there are several complications with the certification of natural remedies by government agencies. First of all, “Cedar Oil” made in North America is often derived from Arborvitae (a cypress), or Eastern Red Cedar (a juniper), but it could be from any of 20 or so “cedars” that aren’t cedars. This, and variations in the extraction process between makers make it impossible to predict the concentration of active ingredients. 

On the other hand, the Natives discovered a great many useful medicines, and the widespread use of Arborvitae suggests that it could be beneficial. I’m currently experimenting with a homemade insect repellent, which includes oil of cedar, to keep ticks off of my dog. I’m reluctant to spray her with conventional insect repellents, knowing that she’ll be licking herself. Early results are mixed, but at least it smells good. 

The Druids Garden website relates a number of Indian stories and beliefs about Arborvitae. It observes, however, that Native peoples, like other cultures, were often ambiguous in their use of the word “cedar”. But the stories came from tribes that originated in the East, and likely involve Thuja occidentalis. In any case, widespread legends from multiple Native groups indicate that Arborvitaes contain powerful spirits that oversee and protect the people. In several other stories, people who wish for long lives are turned into cedar trees. Be careful what you ask for. 

During New Year’s celebrations in China, the aromatic branches of Arborvitae (but probably Thuja orientalis) are used as good luck charms. 

And about the Arborvitae within us. Within your brain’s cerebellum is white matter with a branching pattern resembling a tree. It’s been named the “Tree of Life”, and in keeping with the use of Latin names for anatomy, it’s called the “arbor vitae”. In that light, the idea of a spirit living in the Arborvitae makes perfect sense. 

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