How to Identify and Manage Northern White Cedar

Essential Information on the Arborvitae Cedar

Arborvitae
Northern White Cedar. www.axbocz.net/

Northern white-cedar is a slow growing native North American boreal tree with the scientific name Thuja occidentalis. Arborvitae is another name for the tree in its cultivated and commercially grown form which is planted in yards and landscapes throughout the United States. This nursery-derived version of the white-cedar is prized for the unique flat and filigree sprays made up of tiny, scaly leaves.

 

Northern white-cedar has also been called eastern white cedar and swamp-cedar. The name "arborvitae" meaning "tree of life" was given the tree and was the first North American tree to be transplanted and cultivated in Europe. 

Ethnobotanical history suggests that 16th-century French explorer Jacques Cartier learned from native Americans how to use the tree's foliage to treat scurvy. Scurvy was an insidious disease that ravaged humans that had no ready source of ascorbic acid or vitamin C. A decoction of the exported tree's sap was sold in Europe as a curative medicine.

A record tree in Michigan's Leelanau County measures 18 feet in circumference and 113 feet (34 meters)  in height. 

Where the Northern White Cedar Lives

You will find that the main range of northern white-cedar extends through the southern part of the eastern half of Canada and down to an adjacent northern part of the United States.

Looking at it's U.S. Forest Service range map, you will see specifically that it extends west from the Gulf of St. Lawrence through central Ontario to southeastern Manitoba. Eastern white cedar's southern U.S range extends through central Minnesota and Wisconsin to a narrow fringe around the southern tip of Lake Michigan and east through southern Michigan, southern New York, central Vermont and New Hampshire, and Maine.

 

Northern white-cedar prefers a humid climate and where the annual precipitation ranges from 28 to 46 inches. Although it does not develop well on extremely wet or extremely dry sites, the cedar will do well on cool, moist, nutrient-rich sites and particularly on organic soils near streams or boreal "swamps".

The principal commercial uses of northern white-cedar are for rustic fencing and posts because of the wood's resistance to rot. Other important wood products made from the species includes cabin logs, lumber, poles, and shingles. The wood fiber is also used as paper pulp and particleboard.

Identification of the Northern White Cedar

The "leaf" (if you can call it a leaf) is actually evergreen and scale-like off main shoot sprays. They are 1/4 inch long with long points. Lateral shoots are flattened, 1/8 inch long with short points.

The species is "monoecious" meaning that the tree has both male and female reproductive parts. Female parts are green with 4 to 6 scales and male parts are green tipped with brown scales.

The fruit is a cone, only 1/2 inch long, oblong and protrude upright on the branches. Cone scales are leathery, red-brown and rounded, with a small spine on the tip.

New growth on each twig is green and scale-like and occurring in very flattened foliar sprays.The bark is fibrous, red-brown, weathering to gray.

You will often see diamond-shaped bark patterns and the tree's form is a small to medium sized tree shaped like an arrowhead or a pyramid.

The Commercial Arborvitae Varieties

Probably the most commonly planted Arborvitae planted in the North American landscape is the "Emerald Green" variety. It has great winter color and is one of the most popular hedge plants within its range and is also extensively used outside its range in the Pacific Northwest.

Many arborvitae varieties can be planted as a very reliable, small to medium ornamental in American yards outside the natural range of Thuja occidentalis. You can see more than 100 cultivated varieties used extensively in dooryards, in hedgerows, in borders and as a single large "striking" specimen in a large landscape. You will also see this tree along driveways, building foundations,subdivision entrances, cemetaries, and parks.

White-Cedar has many cultivars, many of which are shrubs. Popular cultivars include:

  • ‘Booth Globe’ 
  • ‘Compacta’
  • ‘Douglasi Pyramidalis’
  • ‘Emerald Green’ - good winter color
  • ‘Ericoides’
  • ‘Fastigiata’
  • ‘Hetz Junior’
  • ‘Hetz Midget’ - slow growing dwarf
  • ‘Hovey’
  • ‘Little Champion’ - globe shaped
  • ‘Lutea’ - yellow foliage
  • ‘Nigra’ - dark green foliage in winter, pyramidal
  • ‘Pyramidalis’ - narrow pyramidal form 
  • ‘Rosenthalli’
  • ‘Techny’
  • ‘Umbraculifera’ - flat topped
  • ‘Wareana’
  • ‘Woodwardii’