Arborvitae and true Cedar are not the same tree, despite common confusion in landscaping and lumber industries. These two conifers belong to entirely separate branches of the plant kingdom, differing significantly in physical structure and evolutionary history. While both offer fragrant, durable wood, their botanical classifications place them far apart, making visual identification straightforward once the differences are understood.
The Botanical Distinction
The formal classification of Arborvitae and true Cedar immediately demonstrates their lack of close relation. Arborvitae is a member of the genus Thuja, which belongs to the Cypress family (Cupressaceae). This family is characterized by scale-like leaves and small, often woody cones. The genus Thuja contains five species, including Thuja occidentalis, commonly known as Northern White-Cedar or Eastern Arborvitae.
True Cedar, in contrast, belongs to the genus Cedrus, placed within the Pine family (Pinaceae). The Pine family includes other well-known conifers like true firs, spruces, and pines. This classification means that a true Cedar, such as the Atlas Cedar (Cedrus atlantica) or the Cedar of Lebanon (Cedrus libani), is more closely related to a common pine tree than it is to any species of Arborvitae. Separation at the family level signifies a profound divergence in their evolutionary paths.
Key Visual Differences
The most immediate way to differentiate these trees is by examining their foliage. Arborvitae foliage consists of small, flat, scale-like leaves pressed tightly against the branchlets, forming flattened, fan-like sprays. These sprays have a soft texture and a characteristic arrangement that makes the entire branch appear layered.
True Cedar foliage, however, is composed of short, sharp, evergreen needles. These needles are arranged in dense clusters or rosettes on small, woody pegs called spurs, or they appear spirally arranged on new growth. This arrangement gives true Cedar a much finer, more textured look than the flat, layered appearance of Arborvitae.
Reproductive structures also provide clear distinctions. Arborvitae produces small, oblong, woody cones, typically less than one inch long, which usually protrude upright on the branches. These cones have leathery scales and remain relatively intact after the seeds are dispersed.
True Cedar produces much larger, barrel-shaped cones that stand upright on the branches, similar to true firs. Unlike most other conifers, these cones disintegrate while still on the tree, shedding their scales to release seeds. This unique shedding pattern leaves only a central spike, or rachis, remaining on the branch.
The bark and growth habit further separate the two plants. Arborvitae generally develops thin, reddish-brown bark that is fibrous and tends to peel or shred in vertical strips. The overall growth habit is often columnar or pyramidal, particularly in cultivated varieties.
True Cedars develop thick, deeply fissured, and often blocky bark as they mature. They typically grow into massive trees with broad, spreading, tiered branches, creating a distinct silhouette from the columnar Arborvitae.
Origins of the Common Name Confusion
The persistent misidentification largely stems from using “cedar” as a common, non-botanical term for any conifer producing fragrant, decay-resistant wood. When early explorers encountered new aromatic trees in North America, they often assigned the familiar name “cedar” to them, even if the plants were unrelated to the true Cedrus species of the Mediterranean and Himalayas. This practice led to many unrelated trees, including Arborvitae, being called “cedar.”
The name “Arborvitae” itself, meaning “tree of life” in Latin, also played a part in the linguistic separation. French explorers gave the name to Thuja occidentalis after learning from Indigenous peoples that the foliage could be used to treat scurvy. However, the aromatic wood of Thuja was so similar in scent and texture to true Cedar wood that the common name “white cedar” or “eastern white cedar” became entrenched in the lumber and horticultural trades.
Adding to the complexity, other North American conifers also bear the confusing “cedar” moniker, such as Eastern Red Cedar (Juniperus virginiana), which is actually a type of Juniper. Ultimately, the term “cedar” became a descriptor of wood quality—fragrant, durable, and moth-repellent—rather than a precise botanical classification. This historical naming convention is the primary reason the question of whether Arborvitae is a Cedar continues to be asked today.