What is a Giant Arborvitae?

A Giant Arborvitae is another name for the Western Red Cedar. This tree, whose scientific name is Thuja pilcata, is an evergreen that is not actually a cedar at all. Instead, the Giant Arborvitae is a member of the cypress family. Pilcata is a Greek word that means "folded in plaits," which describes the tree's leaves. Arborvitae is a Latin word that means "tree of life."

The Giant Arborvitae is indigenous to the Pacific Northwest of the United States and southwest Canada and live for up to 1,000 years. The growth rate of this coniferous tree is two to three feet (.6 to .9 m) per year for most trees. Mature trees are typically between 30 and 50 feet (9 and 15 m) tall with trunks approximately 10 feet (3 m) in diameter. Larger specimens have been known to grow up to 150 feet (45 m) tall and the trunks of those trees can be as big as 22 feet (6.7 m) in diameter. The largest documented tree is the Quinalt Lake Cedar in Quinalt Lake Rain Forest Olympic National Park and is 174 feet (53 m) tall and 19.5 feet (almost 6 m) in diameter.

This cypress tree is most often used for construction, hedges or windbreaks, and shade. The wood is naturally resistant to decay due to a substance called thujaplicin, which is found in many older trees. This weather resistance along with an attractive red color makes it desirable for use in siding and shingles. The wood is also used in decking and indoor closets to deter pests. The wood is sometimes even used for manufacturing guitars because it is easily varnished and can withstand heavy use without warping.

Giant Arborvitae are also grown specifically for their bark. Harvesters carefully strip the bark from the live tree where it is used to make baskets, rope, and other decorative items. The bark will slowly regenerate and as long as no lasting damage was done, the tree will continue to grow.

Hedges of Giant Arborvitae are used interchangeably with many other kinds of cypress, such as the Leyland Cypress, due to the rapid growth rate and how full the mature trees become. Landscapers interested in quickly developing hedges usually plant the trees five to six feet (1.5 to 1.8 m) apart. This spacing will make the trees grow into a hedge windbreak in less than five years. Trimming is necessary for trees planted so close together, so most new trees are planted 10 to 12 feet (3 to 3.6 m) apart so the fully mature trees will be thick but not overcrowded.