Other names for this coniferous, evergreen tree include Northern White-Cedar and American Arborvitae. It has a narrow, pyramidal shape, which attains a height of 20-40 feet and a spread of 10-15 feet. This tree is normally found in swampy areas or rocky hillsides, growing in full sun to shade, and in moist, well-drained soils. Commonly cultivated and grown as a screen or hedge, its dense foliage provides good shelter and nesting sites.