The common confusion over whether redwood is a type of cedar stems from the similar appearance and shared commercial uses of their lumber. Both woods are frequently used in outdoor construction and prized for their natural resistance to decay and insects, which leads to their grouping in the marketplace. Despite sharing a general reddish-brown color, they are fundamentally distinct in their botanical classification. Understanding their scientific identity and physical properties is necessary to clarify the unique characteristics of each wood.
The Definitive Answer and Botanical Identity
Redwood and cedar are not the same tree; they belong to different genera. Both fall under the broader Cupressaceae family, also known as the cypress family. The commercially significant Redwood species are the Coast Redwood (Sequoia sempervirens) and the Giant Sequoia (Sequoiadendron giganteum). These species are unique enough to be placed in their own subfamily, Sequoioideae.
True Cedars belong to the genus Cedrus and are part of an entirely different family, Pinaceae, which includes pines and firs. However, the wood commonly sold as “cedar” in North America is typically Western Red Cedar (Thuja plicata). Western Red Cedar is a member of the Cupressaceae family, like Redwood, but belongs to the genus Thuja, making it a botanical cousin.
This distinction highlights the problem with common names, as “cedar” is often applied loosely to various aromatic softwoods. Redwood is a sequoia, while the wood most people call cedar is a Thuja. The commercially available Western Red Cedar is more closely related to cypresses and junipers than it is to the true Cedrus species of the Mediterranean and Himalayas.
Key Physical Differences in the Wood
The wood of Redwood and Western Red Cedar exhibits differences in appearance, density, and aromatic properties. Redwood heartwood is generally a deeper, richer reddish-brown with a more uniform coloration. Cedar, particularly Western Red Cedar, often features a lighter, more variegated color palette, ranging from pale honey yellow to reddish-brown, sometimes with streaks of pink or white.
Redwood is typically denser and harder than cedar. Redwood has a Janka hardness rating approximately 23% higher than Western Red Cedar, making it more resistant to impact and wear. The grain structure also differs, with Redwood often displaying a straighter and tighter grain, which contributes to a sleek finish.
Both woods are aromatic due to natural compounds that repel insects and resist decay, but their scents are distinct. Western Red Cedar is known for a strong, pleasant aroma often utilized in closets and chests. Redwood also possesses aromatic quality, but its scent is less pronounced and less often noted as a defining characteristic.
Why the Confusion Exists
The confusion between redwood and cedar largely stems from the commercial use of “cedar” as a catch-all term for durable, reddish softwoods. Many species are marketed using “cedar” in their common name, despite not belonging to the Cedrus genus. This broad naming convention causes the general public to group Redwood and Western Red Cedar together.
A primary factor in the conflation is the shared natural resistance to decay and insects. Both species contain natural tannins and extractives that provide excellent longevity and making them highly desirable for similar outdoor applications. This suitability leads to them being used interchangeably for decking, siding, and fencing.
Furthermore, both trees belong to the same broader Cupressaceae family, which suggests a degree of relatedness despite being in different genera. This shared lineage means they evolved similar characteristics, such as rot-resistant chemicals. The visual similarity of their reddish hues further solidifies this common misconception.