Arborvitae

Arborvitae is the wood of Thuja occidentalis, a small-to-medium evergreen conifer of the cypress family (Cupressaceae) native to eastern North America, from the Canadian Maritimes and Quebec through the Great Lakes and New England south along the Appalachians. In the timber trade it is almost universally sold as Northern White Cedar (or Eastern White Cedar); "arborvitae" — Latin for "tree of life" — is the horticultural name, since the same species is one of the most widely planted landscape hedges in the world. The tree favors cool swamps, limestone outcrops, and stream banks, and though it can be very long-lived it stays modest in size, so the wood comes in relatively narrow, often knotty stock.

At a glance the wood is pale, light, and soft, with a distinct spicy-cedar aroma. This sample shows the typical concentric growth rings with a fine radial grain and a pale tan to cream color. What makes the species valuable is not strength — it is one of the softest and weakest commercial conifers — but its outstanding natural decay resistance and feather-light weight, which have made it a traditional choice for shingles, fence posts, and boat components for centuries.

Heartwood is a light straw-brown to pale tan, sometimes with a faint pinkish or reddish cast, while the narrow sapwood is nearly white; the contrast is modest and the overall impression is of a pale, uniform, creamy wood, matching the pale tan to cream seen on this sample. Growth rings are usually clearly marked as concentric bands, giving a fine, straight radial grain, and the texture is fine and even with a low, soft luster. Knots are common, since the species is small and heavily branched.

It is a genuinely low-density softwood, with a Janka hardness around 320 lbf — soft, among the lowest of any commercial North American wood, well below pine or spruce. It is correspondingly low in weight, strength, and stiffness, dents easily, and is not chosen for load-bearing structural roles.

Its standout trait is natural durability: the heartwood is rated durable to very durable, with strong resistance to decay and reasonable resistance to insects even in wet, ground-contact, and exposed conditions. That rot resistance, combined with its light weight and dimensional stability, is the reason the wood has endured in outdoor use despite its softness. Note that only the heartwood is durable; the pale sapwood is not.

The classic uses all exploit rot resistance and low weight rather than strength. Northern White Cedar is the traditional wood for wooden shingles and shakes, and for fence posts, rails, and poles that sit in the ground. It is also the standard material for canoe ribs and planking and for lightweight small-boat construction, where its bendability and buoyancy matter.

Beyond that it appears in log-cabin siding and log homes, lakeside decking and dock timbers, cabin and outdoor furniture (including rustic and "cedar" garden furniture), tanks and tubs, saunas, novelties, carvings, and closet and chest lining, where the aromatic character is valued. Because the tree is small and knotty, it is rarely used for fine furniture or wide panels; its niche is durable outdoor and utility work. The living tree is far more familiar as a planted hedge and screen than the lumber is in the shop.

Arborvitae is very easy to work with both hand and machine tools thanks to its softness and low density, and it holds a knife or gouge well for carving. The main cautions come from that same softness: it dents and crushes easily, fuzzes or tears around knots and on end grain, and does not hold crisp fine detail, so sharp, keen tools and light finishing cuts give the cleanest surface. It nails and screws readily and rarely splits, though fasteners do not hold with great strength in such soft, low-density stock; ring-shank or larger fasteners help in exterior work.

It glues and finishes well and dries quickly and easily with little degrade, and its stability once dry is good. As with most cedars, the resin/oil content can occasionally interfere with the cure of some finishes, so a test is worthwhile on projects that must hold paint.

On safety, the aromatic wood and its dust can cause reactions in sensitive workers: reported effects include respiratory and nasal irritation and skin sensitization, in common with other members of the Thuja/cedar group. The foliage and oil (thujone) are toxic if ingested, but this is a concern for the plant rather than the dry lumber. Use dust extraction and a respirator when machining or sanding. The species is not listed on CITES and is not endangered.

Northern White Cedar is a regional specialty rather than a national commodity: it is common and affordable within its range in the northeastern U.S. and eastern Canada — where shingles, posts, and cedar-strip canoe stock are readily found — but harder to source and more of a novelty elsewhere. Because the tree is small and knotty, clear, wide, or long boards command a premium, while knotty utility grades, posts, and shingle bolts are inexpensive.

The species is abundant, widely planted, and not under any trade restriction: it is not listed on CITES and is not considered threatened. FSC-certified and responsibly harvested stock is available from managed northern forests. As a slow-growing but common and self-regenerating native conifer, its supply is secure, and it is generally regarded as a sustainable choice for durable outdoor woodwork.