Giant arborvitae | The Morton Arboretum

Giant arborvitae is a dense, stately evergreen tree native to the Pacific Northwest, often used as a specimen or for screening. The fresh green foliage consists of flat sprays formed by overlapping scales. The name “arborvitae,” meaning “tree of life,” comes from the belief that Native Americans used such trees for medicinal purposes. The tree supplies seeds and shelter for birds but is less appealing to deer. In nature, giant arborvitae can reach 70 feet in height, but they are rarely that tall in cultivation. There are many cultivars that vary in height and other characteristics. On some varieties, the foliage changes color in winter.

Family (English) Cypress
Family (botanic) Cupressaceae
Planting site Residential and parks
Tree or plant type Tree, Shrub
Foliage Evergreen (foliage year-round)
Native locale North America
Size range Medium shrub (5-8 feet), Large shrub (more than 8 feet), Compact tree (10-15 feet), Small tree (15-25 feet), Medium tree (25-40 feet), Large tree (more than 40 feet)
Mature height 50-70 feet
Mature width 15-25 feet
Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
Hardiness zones Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7
Soil preference Moist, well-drained soil
Tolerances Alkaline soil, Dry sites, Occasional drought, Wet sites
Season of interest early winter, midwinter, late winter, early spring, mid spring, late spring, early summer, midsummer, late summer, early fall, mid fall, late fall
Flower color and fragrance Inconspicuous
Shape or form Narrow, Pyramidal, Round, Upright
Growth rate Slow
Transplants well Yes
Wildlife Birds, Browsers, Cavity-nesting birds, Small mammals
Has cultivars Yes

Native geographic location and habitat:

Giant arborvitae is native to forests of the Pacific Northwest of North America. In nature, it’s found on slopes, along stream banks, and in swampy areas.

Bark color and texture:

Giant arborvitae bark is grayish-brown to reddish-brown, with stringy fibers and a network of ridges and shallow furrows.

Leaf or needle arrangement, size, shape, and texture:

It has flat, horizontal spreading sprays of scale-like evergreen leaves that are soft green.

Flower arrangement size and shape:

Flowers are inconspicuous, with separate male and female flowers.

Cone description:

Giant arborvitae has tiny oval cones which mature from green to brown in color.

Attracts birds:

Browsers, cavity-nesting birds, and small mammals use this tree.

**Deer Proof™ giant arborvitae (Thuja plicata ‘KLMfive’):**

A tall, narrow, pyramidal tree, growing 40 to 50 feet high and 15 to 25 feet wide, this is a medium to fast grower with excellent cold hardiness. It has a loose, narrow habit with dark green horizontal branching foliage that has yellow tips. It is useful as a specimen or hedge or in groupings or screens. Deer do not favor this cultivar.

**Excelsa giant arborvitae (Thuja plicata ‘Excelsa’):**

A pyramidal tree, growing 25 to 35 feet high and 10 to 15 feet wide. It has a loose habit with glossy, green horizontal branching foliage that turns yellow-green in winter. It is useful as a specimen, hedge, in groupings, or screens.

**Green Giant arborvitae (Thuja ‘Green Giant’):**

This is a hybrid of T. plicata and T. standishii. It may grow up to 40 feet tall. This cultivar maintains good green color in winter.

**Hillier giant arborvitae (Thuja plicata ‘Hillieri’):**

This cultivar has a spreading form, growing 7 to 10 feet high and wide. The tree’s blue-green foliage turns bronze-brown in winter. It is useful as a specimen or for hedges, groupings, and screens.

**Spring Grove® giant arborvitae (Thuja plicata ‘Grovepli’):**

This tree is 25 feet high by 8 feet wide. It is considered deer resistant.

**Virescens giant arborvitae (Thuja plicata ‘Virescens’):**

A narrow, pyramidal small tree growing 20 to 30 feet high and 10 to 20 feet wide. The foliage is glossy and bright green year-round. It is useful as specimen or for hedges in formal and semi-formal plantings, groupings, and screens.