Thuja Occidentalis L.Cupressaceae

Distribution
Thuja Occidentalis is a wonderful species of thuja being an evergreen coniferous tree of the cypress family Cupressaceae. It is native to the large area of northeastern U.S. and southeastern Canada, stretching from central Saskatchewan, going east to New Brunswick, and then south to eastern along the Appalachian Mountains of Tennessee. Thuja Occidentalis is often referred to by alternative names and also known as Eastern Arborvitae, American Arborvitae, Techny Arborvitae, Arborvitae, Northern Whitecedar, and Eastern Whitecedar. Alternatively called or described as a White Cedar, it is not a cedar and not related to the Australian deciduous tree, the Chinaberry, Melia Azedarach, which is also known as the White Cedar.

Description, Size and Age
As a relatively small to medium tree, Thuja occidentalis grows between 33-66 feet or 10m-20m tall with rare occasional much larger specimens reaching 100-feet or 30m tall with trunk diameter ranging from 15-inches to 5-feet or 0.4m-1.5m. The largest known specimen reached to well over 111-feet or 34m tall with a trunk nearly 5-feet or 175 cm diameter. This magnificent specimen is located in South Manitou Island in Leelanau County, Michigan. The bark is red-brown with obvious furrows, and peels off in narrow, longitudinal strips. The foliage growth forms into flat sprays with scale-like leaves 3/16th-inch or 4.75mm long. When cones are produced, they are physically small and slender with a yellow-green coloring, then ripening to brown, and are 1/2 inch or 12.5mm long and 3/16th-inch or 4.75mm broad, with 6-8 overlapping scales. The oldest known living specimen is over 1,000 years old, however a dead specimen had over 1,500 growth rings. These rare old trees, despite their age, remain small and stunted having endured difficult growing conditions.

Natural Habitat and Extreme Conditions
Thuja occidentals’ preferred natural habitat is wet forests. It is extremely prolific in swamps where it excels and dominates its environment, so much so that other, larger and faster-growing trees do not get a look-in and just cannot compete successfully. They are also, found on other less competitive sites such as cliffs where, luckily, conditions actively allow them to become long-lived specimens. Places such as cliffs maybe less competitive, but that is only because Thuja has that capacity to eke out a living in such poor conditions, whereas the lesser competing trees just could not cope and survive there, so it wins by default!.

Natural Protection and Threats From Deer
Rocky cliffs and such difficult areas provide natural protection from the onslaught of grazing deer and also protect from the ravages of wildfire as the rock maintains a barrier to fire, plus there is much less combustible material to catch alight. However, not all the trees are lucky enough to be protected as very high deer numbers endanger Thuja occidentalis populations in many areas. Deer relish stripping the tender evergreen foliage which is an essential winter food enabling them to survive and prosper. Thuja occidentalis would not be too happy with the many hunting associations that desire and actively encourage healthy deer populations for the benefit of their members! The good news is that, Thuja occidentalis even though threatened in some areas is not an endangered species and will continue to thrive into the foreseeable future.

Natural Choice For Hedges and Windbreaks
Grown as a much sought after, high quality ornamental tree, Thuja Occidentalis is a natural choice for screens and hedges where privacy or windbreaks are required. Today over 300 named cultivars are available for garden use. Notable horticultural trade species include Ellwangeriana, Degroot's Spire, Hetz Wintergreen, Lutea, Rheingold, Smaragd (Emerald Green), Techny, and Wareana. Introduced into Europe around 1540, today the species are widely cultivated especially in parks and cemeteries.

Health Snippet 
Thuja occidentalis has beneficial therapeutic oils used in organic medications that claim to eliminate warts, including the Human papillomavirus although apparently not scientifically proven.

Thuja Occidentalis  L.Cupressaceae