Tuesday, March 3, 2020
Arborvitae - Thuja occidentalis
Arborvitae - Thuja occidentalis is monoecious evergreen tree that generally reaches heights of 40-50 feet tall, although it has the potential to grow much taller in ideal conditions. It is a native northern Cypress with scale like leaves, and flattened twigs that are grouped in fan shaped sprays with bilaterally symmetric cones. Found mostly on limestone derived soils, in swampy areas, riparian areas, and on cliff /talus from 0-900 m. It is common from Ontario and New Brunswick in the north, south through the Appalachians of North Carolina and Tennessee. It is also commonly called Northern White Cedar, American Arborvitae, Eastern Arborvitae, or Cedar Blanc.
Image Citation: (Foliage) Paul Wray, Iowa State University, Bugwood.org
The bark of the Arborvitae is Red-Brown in color and becomes gray with age. The bark is thin and fibrous becoming fissured and forming long strips with age. The pollen cones are 1-2 mm long reddish in color. The seed cones are ovoid 9-14 mm long, green maturing to brown with 2 pairs of woody, fertile scales, each one is longer then it is wide. The leaves are scale like, flattened 1-4 mm long, 1-2 mm wide, pointed and dull yellow-green on the upper and lower surface with visible glands and lateral leaves near twig tips.
Image Citation: (Bark) Paul Wray, Iowa State University, Bugwood.org
It is written that in 1536 an extract from the foliage of the Arborvitae saved the lives of Jacques Cartier and his crew who were suffering from scurvy during their second discovery voyage to Canada, they in turn named the tree Arborvitae which is Latin for "tree of life". They brought the tree home with them to Europe, making it the first North American tree to be introduced to Europe. Since that time, there have been more then 120 cultivars discovered and named. This sheer number makes it one of the most popular trees in horticulture today. Arborvitae is also one of the longest lived trees in Eastern North America, it has been documented to live up to 1890 years.
Image Citation: (Row planting) Jason Sharman, Vitalitree, Bugwood.org
Arborvitae is a very common planting in both residential and commercial settings. It is recommended for hardiness zones 3-7 and holds it foliage year round. This tree adapts very well to both shearing and shaping and naturally grows in a pyramidal shape. It is often used as a natural fencing or planted in rows to create a hedgerow/screening effect.