727 Thuja occidentalisCommon Names: eastern white cedar, American arborvitae Family: Cupressaceae (cypress Family)
The wild eastern white cedar is a symmetrical evergreen conifer that usually gets 40-60 ft (12.2-18.3 m) tall. It is narrowly cone-shaped with a tight, compact crown. The trunk is sometimes buttressed at the base, and the thin, reddish brown bark is cut with furrows and shreds in thin strips. Branches start near the ground in open-grown trees; those in a forest setting may be devoid of branches for the lower third of their height. The branches are short and horizontal and the branchlets are flattened and held in fanlike horizontal planes. The leaves are like scales, closely attached to the compressed branchlets. Foliage is pleasantly fragrant, dull yellowish green, turning bronze in winter. Cones are small, about 0.5 in (1.3 cm)long, egg-shaped and green at first, turning reddish brown when mature in autumn. Eastern white cedar (a.k.a. American arborvitae) is similar to oriental arborvitae (Platycladus orientalis), but the latter tends to have more than one stem, and holds its sprays of foliage in vertical rather than horizontal planes.
More than 140 cultivars have been selected for ornamental use; these usually are called American arborvitae, and most are much smaller and shrubbier than the wild species. Most American arborvitae cultivars are rounded, and billowy, but some are narrow and cone-shaped. 'Filiformis' grows in a mound with long thin weeping branchlets. 'Rheingold' is bushy and flat-topped, 3-6 ft (0.9-1.8 m) tall with golden foliage. 'Caespitosa' is like a tiny cushion, to 12 in (30.5 cm) high and 16 in (40.6 m) across. 'Pendula' has branches that ascend, then droop, and usually requires some kind of support. 'Techny' grows in a pyramid to 12 ft (3.7 m) tall and stays dark green all year long; it's best for hedges and is one of the most popular cultivars in the U.S. 'Elegantissima' is narrowly conical, to 12 ft (3.7 m) tall, and has yellow-tipped leaves.
Eastern white cedar, Thuja occidentalis, is native to NE North America from Nova Scotia and Quebec, west to Manitoba, and south to Minnesota, Ohio, New York and northern New England. Isolated populations occur on some of the higher peaks in the Appalachian Mountains of Pennsylvania, Virginia, West Virginia and North Carolina. Wild eastern white cedar generally grows in swamps and wet forests, on neutral or alkaline soils, often associated with limestone.
CultureProtect young trees from porcupines and moose. Light: Full sun to partial shade. Moisture: American arborvitae likes a humid environment and grows best in areas with high snowfall. Mulch well to keep the soil from drying out. Arborvitae tolerates wet soil. Hardiness: USDA Zones 2 - 7. American arborvitae does not do well in dry-summer climates, and generally performs poorly on the middle Atlantic coastal plain. Propagation: Eastern white cedar, the wild tree, is propagated from seed. American arborvitae, the cultivated form, is propagated from semi-ripe heeled cuttings taken from the current season's growth and rooted with mist and bottom heat.
The tall, pyramidal cultivars of American arborvitae are good accent or specimen trees. Small bushy cultivars are commonly used in foundation plantings, especially at corners. Very small cultivars are useful in rock gardens. Arborvitae responds very well to pruning, and is easily shaped into a formal hedge. But a row of freely branching specimens makes a nice hedge too. Some insist that American arborvitae is overused in suburban landscapes. But these are durable and carefree evergreens and will always have a place, like grass, in the home yard.
Eastern white cedar, the tree, is valued for its soft, rot-resistant, easily worked wood which is made into canoe ribs, toboggans, shingles and fence posts. Native Americans used various concoctions of white cedar for a variety of ailments, and early French settlers gave it the name, "arborvitae" - tree of life.
Steve Christman 7/16/00; updated 10/28/04