The size of a cedar tree is complex because the term “cedar” refers to many different species across several botanical families. The name is often applied to any conifer that produces fragrant, durable wood, leading to confusion regarding their ultimate height and spread. A tree labeled “cedar” could grow to be a towering forest giant or remain a modest landscape specimen. Understanding the specific species is the only way to accurately predict its mature size, as dimensions vary dramatically.
Taxonomical Confusion
The massive variation in size is rooted in the misapplication of the common name “cedar” across different genera. Botanically, the only “True Cedars” belong to the genus Cedrus, native to the Mediterranean region and the Himalayas, and are part of the Pinaceae (Pine) family. These include the Atlas Cedar (Cedrus atlantica) and the Deodar Cedar (Cedrus deodara), characterized by true needles clustered on short shoots. The majority of trees commonly called cedars in North America are “False Cedars” belonging to the Cupressaceae (Cypress) family. This group includes popular landscaping trees from genera like Thuja (Arborvitae), Juniperus (Juniper), and Chamaecyparis (False Cypress), which feature scale-like foliage and small, often berry-like cones.
Maximum Dimensions of Major Species
The Western Red Cedar (Thuja plicata), a false cedar, commonly reaches 150 to 230 feet (45 to 70 meters) tall in the wild with a trunk diameter of up to 23 feet (7 meters). These giants of the Pacific Northwest can live for over a thousand years and form massive, buttressed bases. Among True Cedars, the Deodar Cedar (Cedrus deodara) from the Himalayas can reach up to 197 feet (60 meters) in its native range. In cultivation, however, it is more commonly seen at a mature height of 40 to 50 feet (12 to 15 meters) and develops a substantial trunk up to 10 feet (3 meters) in diameter.
A significantly smaller specimen is the Eastern Red Cedar (Juniperus virginiana), which is technically a juniper. This species typically grows to a height of 40 to 50 feet (12 to 15 meters) with a spread of 8 to 20 feet (2.4 to 6 meters) in a landscape setting. Although exceptional individuals reach nearly 90 feet (27 meters), this species often functions as a dense, columnar screen.
Growth Rates and Maturity Timelines
The Deodar Cedar exhibits a moderate growth rate, typically adding 13 to 24 inches (33 to 61 centimeters) of height per year. Under favorable conditions, this can increase to around three feet annually, but reaching its maximum size is a relatively slow process. The Western Red Cedar also grows at a medium rate, often reaching 40 feet within 10 to 20 years, making it a popular choice for privacy screens. In contrast, the Eastern Red Cedar is considered slow-growing, though it can still add 1 to 2 feet (30 to 60 centimeters) per year in ideal conditions. This species reaches its mature height within 10 to 20 years.
How Environment Affects Cedar Size
The final dimensions of any cedar species are heavily influenced by local environmental conditions, not solely by genetics. Competition for resources, particularly in dense forest settings, shapes the tree’s form and size. Water availability and soil quality play significant roles in determining a tree’s vigor and ultimate height. Most cedars require well-drained soil, and growth is severely stunted on dry or infertile sites. Climate is also a factor, as seen with the Yellow-cedar, which is declining due to warming winters that reduce protective snowpack, leaving its roots vulnerable to damaging spring freezes. Environmental stressors like prolonged drought or extreme cold can weaken trees, making them susceptible to secondary threats like bark beetles and fungal infections.