The "National Audubon Society Field Guide to Trees" maintains that the northern white cedar (Thuja occidentalis) was likely the first of the North American tree species brought back to Europe by explorers, around 1536. The Latin word for this species, "arborvitae," translates into "tree of life." Thuja occidentalis today is an excellent landscaping tree that fulfills multiple purposes.
The online resource Nearctica describes the northern white cedar as having a wide base with a compact, conical crown. The tree averages between 40 and 60 feet tall under good circumstances and Thuja occidentalis has a trunk diameter that can reach 3 feet. The evergreen foliage resembles scales arranged in four opposite rows. The color is a shiny green shade, except in the fall and in times of drought when it can turn yellowish-green or brown . The bark shreds easily on the trunk and the branches and is reddish-brown to gray. The female trees feature oblong 1/2-inch-long cones that occur in clusters and grow erect on the limbs.
Thuja occidentalis grows in the wild in the eastern portion of the continent, with its northern range being from southeast Manitoba in Canada to Nova Scotia. The tree is native to all of Maine and the upper halves of Vermont and New Hampshire. Northern white cedar grows in northern New York State, throughout the Great Lakes States and in various locations in southern New England and throughout the Appalachian Mountains.
Growing Conditions and Uses
This cedar species does well in moist damp climates and grows its best, like most plants, in fertile, loamy soil. The northern white cedar will withstand soils with alkaline and acidic pH levels and needs a location where it receives full sunshine most of the day. Thuja occidentalis is a tree you can trim and shear into a hedge when you plant several close together. The species also serves as a windbreak, screen, border plant and foundation plant.
The National Forest Service warns the effects of salt spray from highway de-icers can kill branches on the northern white cedar. For this reason, avoid planting this species too close to roadways and driveways. Snow and ice, in particularly hard winters, can break branches and cause developing white cedars to lean as they grow. Strong wind can knock over the older trees, especially in wet areas. This tree does not tolerate flooding well, which is another point to consider when selecting a growing site.
The University of Connecticut Plant Database lists dozens of hybrids of Thuja occidentalis, with many being dwarf cultivars. These include 'Hetz Midget,' which grows slowly and seldom exceeds 3 feet in height. 'Little Gem' is another 3-foot-tall hybrid, but the 'Little Giant' cultivar can be 6 feet high and round. The 'Emerald' cultivar of Thuja occidentalis has a vibrant green color, even in the midst of winter, and grows to 15 feet high.