Cedar wood is a popular softwood valued for its aromatic properties and natural durability. Its color is not a single, uniform shade, varying significantly based on the species and whether the wood comes from the inner heartwood or the outer sapwood. A fresh cut piece of cedar can range from a pale yellow-white to a rich violet-red, establishing a wide spectrum of natural hues.
The Natural Color Spectrum of Cedar
The most common commercial varieties of cedar present distinctly different color profiles when first milled.
Western Red Cedar (WRC)
This highly sought-after species features heartwood that typically ranges from a light reddish-brown to a deeper, sometimes pinkish, brown. This heartwood often displays random streaks or bands of darker red or brown areas, providing a nuanced color palette.
Eastern Red Cedar (ERC)
The heartwood of ERC is known for its more vibrant tones, often appearing as a reddish or violet-brown when freshly cut. This wood can show a distinct purple-red tinge and is the most strongly aromatic of the common cedars.
Northern White Cedar (NWC)
NWC offers a much lighter appearance than its red counterparts, often featuring heartwood that is a pale straw-brown or a very light reddish-brown. This subtle coloration makes the grain less pronounced.
Both WRC and ERC are ringed by sapwood, which is consistently a pale yellow or nearly white color. The sapwood of NWC is almost white, sometimes making the line between the two layers difficult to distinguish.
The Chemical Basis of Cedar’s Hue
The characteristic colors of cedar wood are primarily due to natural compounds known as extractives. These chemicals are deposited in the heartwood as the tree matures, serving multiple functions beyond providing pigment.
Specific groups of extractives, including polyphenolic lignans and tropolones, are responsible for the red and violet hues. These compounds are highly concentrated in the heartwood. They not only create the rich red-brown colors but also provide the wood with its natural resistance to decay and insect attack.
Tannins, another natural extractive, contribute to the brown and red coloration. When water interacts with these chemicals, they can leach out, sometimes leaving reddish-brown stains on surrounding materials. The presence of extractives makes the heartwood significantly more durable and darker than the pale, less resistant sapwood.
How Cedar Color Changes Over Time
When cedar is installed outdoors without a protective finish, its color inevitably changes through weathering. The two primary environmental factors driving this transformation are ultraviolet (UV) light from the sun and moisture from rain.
UV radiation initiates the process by breaking down chemical bonds in the wood’s surface layer, targeting the lignin and colored extractives. As these compounds degrade, rainfall washes them away. This leaching process reveals the underlying cellulose fibers, which are naturally a pale, silvery-gray color.
This transition to a silvery-gray patina is a purely surface-level change and does not diminish the wood’s inherent resistance to decay. Depending on exposure, this uniform color can develop quickly, often being noticeable within six months and fully established within one to two years. Persistent moisture, however, can lead to darker discoloration or black spots. This uneven staining is often the result of mold and mildew growth, such as the fungus Aureobasidium pullulans, rather than simple sun bleaching.