How to Manage and Identify Arborvitae

arborvitae tree
(Joshua Mayer/Wikimedia Commons/CC BY-SA 2.0)

White-cedar is a slow-growing tree that reaches 25 to 40 feet in height and spreads to about 10 to 12 feet wide, preferring a wet or moist, rich soil. Transplanting is fairly easy and is a popular yard specimen in the United States. Arborvitae likes high humidity and tolerates wet soils and some drought. The foliage turns brownish in winter, especially on cultivars with colored foliage and on exposed sites open to the wind.

Specifics

Scientific name: Thuja occidentalis
Pronunciation: THOO-yuh ock-sih-den-TAY-liss
Common name(s): White-Cedar, Arborvitae, Northern White-Cedar
Family: Cupressaceae
USDA hardiness zones: USDA hardiness zones: 2 through 7
Origin: native to North America
Uses: hedge; recommended for buffer strips around parking lots or for median strip plantings in the highway; reclamation plant; screen; specimen; no proven urban tolerance

Cultivars

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’

Description

Height: 25 to 40 feet
Spread: 10 to 12 feet
Crown uniformity: symmetrical canopy with a regular (or smooth) outline, and individuals have more or less identical crown forms
Crown shape: pyramidal
Crown density: dense
Growth rate: slow
Texture: fine

History

The name arborvitae or "tree of life" dates from the 16th century when the French explorer Cartier learned from the Indians how to use the tree's foliage to treat scurvy. A record tree in Michigan measures 175 cm (69 in) in d.b.h. and 34 m (113 ft) in height. The rot- and termite-resistant wood is used principally for products in contact with water and soil.

Trunk and Branches

Trunk/bark/branches: grow mostly upright and will not droop; not particularly showy; should be grown with a single leader; no thorns
Pruning requirement: needs little pruning to develop a strong structure
Breakage: resistant
Current year twig color: brown; green
Current year twig thickness: thin
Wood specific gravity: 0.31

Culture

Light requirement: tree grows in part shade/part sun; tree grows in full sun
Soil tolerances: clay; loam; sand; slightly alkaline; acidic; extended flooding; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: low
Soil salt tolerance: moderate

Bottom Line

Northern white-cedar is a slow growing native North American boreal tree. Arborvitae is its cultivated name and commercially sold and planted in yards throughout the United States. The tree is identified primarily by unique flat and filigree sprays made up of tiny, scaly leaves. The tree loves limestone areas and can take full sun to light shade.
Best used as a screen or hedge planted on 8 to 10- foot-centers. There are better specimen plants but it can be placed at the corner of a building or other area to soften a view. Many of the natural stands in the United States have been cut. Some remain in isolated areas along rivers throughout the East.