Thuja occidentalis
Common Name: American arborvitae
Type: Needled evergreen
Family: Cupressaceae
Native Range: Eastern North America
Zone: 2 to 7
Height: 20.00 to 40.00 feet
Spread: 10.00 to 15.00 feet
Bloom Time: Non-flowering
Bloom Description: Non-flowering
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Leaf: Evergreen
Other: Winter Interest
Tolerate: Clay Soil, Black Walnut, Air Pollution

Culture

Grow in average, medium moisture, well-drained soils in full sun to part shade. Somewhat wide range of soil tolerance, but prefers moist, neutral to alkaline, well-drained loams (especially of some limestone content). Intolerant of dry conditions. Best in full sun, but generally appreciates some light afternoon shade in hot summer climates such as the St. Louis area. Avoid full shade. Avoid exposed, windy sites.

Noteworthy Characteristics

Thuja occidentalis, commonly known as American arborvitae, Eastern arborvitae, Eastern white cedar or Northern white cedar, is a dense, conical to narrow-pyramidal (sometimes maturing to broad-pyramidal), often single-trunked, evergreen tree that is native to eastern and central Canada south to northern Illinois, Ohio and New York with scattered populations further south in the Appalachians to North Carolina. Mature trees may reach 40-60' tall in the wild over time, but in cultivation typically grow much smaller to 20-30' tall. Scale-like, aromatic, yellow-green to green foliage appears in flattened sprays. Red-brown bark will exfoliate on mature branches and trunks.

The common name of arborvitae (tree of life) comes from early French settlers to North America who learned from Native Americans that the tree’s foliage could be used to treat scurvy.

Problems

No serious insect or disease problems. Leaf blight may cause some foliage to spot and drop. Watch for canker. Leaf miner may damage leaf tips. Bagworms, mealybug, scales and spider mites are occasional visitors. Foliage may show some winter burn (turns yellow-brown) in exposed sites. Susceptible to damage/stem breakage in winter from ice and snow accumulations.

Garden Uses

Foundations and landscapes. A very large number of compact to dwarf cultivars of this plant have become very popular.