Northern White Cedar

Seeing the Forest Through its Trees Part IX

By Larry Ely

Thriving where other trees struggle, Northern white cedar quietly shapes the wetlands and forests of our region.

Northern white cedar (Thuja occidentalis), also called arborvitae, is native to our region and sometimes called swamp cedar because of its preferred habitat. Hybridized widely by nurseries for landscaping, the Arborvitae name may sometimes be used for other species of conifers in commercial sales.

Arbor Vitae is Latin for “Tree of Life,” a name based on its medicinal qualities, although it is sometimes attributed to the tree’s long life span, exceeding 200 years. The name most likely resulted from explorer Jacques Cartier’s 1535 Canada expedition when natives provided tea, high in Vitamin C, from the tree’s needles and bark to cure the expedition’s scurvy. Cartier returned with specimens to Paris, making it one of the first American trees introduced to Europe.

Dense stands of northern white cedar are most abundant in the northern and eastern sections of Maine and are not as extensive in our region. They are generally found here in localized swamps and seepage areas with nutrients supplied by running water along our lower mountain slopes though not found in acid bogs. These cedars are  most often found in New Hampshire along the Connecticut River in Coos County.

Northern white cedar is cold hardy, reaching the arctic tree line in Canada, and it grows well in regions of cooler summers and short growing seasons. Often associated with soils influenced by limestone or other calcium-rich bedrock, it is one of the few northeastern conifers that thrives on alkaline sites. It out-competes other conifers in wet swamps where larger trees struggle, and, while the tree might reach 60 feet with a three-foot diameter, it is slow growing and often found as a shrub or small tree in size. A one-inch trunk might be the result of 10 to 20 summers’ growth on poor sites. Older trees often have heavily buttressed and twisted trunks with two or more stems above their shallow roots. The shallow root system, especially in wet soils, makes it prone to wind-throw, and thin bark and resins make it susceptible to wildfire. Resins on the leaves’ undersides give the tree its special woody camphor-like aroma.  

Small seed cones grow in large clusters on the ends of branches and the scaly cones release two winged seeds from each of its inner four scales.

The tree is easily identified by its fanlike branches with quarter-inch scaly leaves in flat sprays. Small seed cones grow in large clusters on the ends of branches, and those scaly cones release two winged seeds from each of their inner four scales. The tree also reproduces by layering when lower branches on the ground produce vertical sprouts and through tipped over trees with sprouts rising from the buried tree. Layering usually accounts for half the tree’s reproduction, and tip-overs often result in a dense straight line of trees. 

Cedar is heavily winter browsed by deer and much less so by moose, and its seeds are favored by pine siskin and other finches. The rot resistant wood is the lightest softwood in our region and has many uses including shingles, posts, and it was even used for making hope chests with a belief that the wood repelled moths.

The common name for this tree is a misnomer, for the tree is not a member of the Cedrus genus, but of the Cypress Family and the genus Thuja -  a good reason for using the Latin name Arborvitae for species.

This is part of a continuing series looking at the life of the common trees in our Mahoosuc Mountain Region.

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