Giant arborvitae

A mature specimen of giant arborvitae.

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 rarely are that tall in cultivation. There are many cultivars that vary in height and other characteristics. On some varieties, the foliage changes color in winter. 

This plant has some cultivated varieties. Go to list of cultivars.

Botanical name:

Thuja plicata

All Common Names:

giant arborvitae, western arborvitae

Family (English):

Cypress

Family (Botanic):

Cupressaceae

Tree or Plant Type:

  • Shrub,
  • Tree

Foliage:

  • Evergreen (foliage year-round)

Native Locale:

  • North America

Planting Site:

  • Residential and parks

Landscape Uses:

  • Hedge,
  • Massing,
  • Screen,
  • Specimen

Size Range:

  • Large tree (more than 40 feet),
  • Medium tree (25-40 feet),
  • Small tree (15-25 feet),
  • Compact tree (10-15 feet),
  • Large shrub (more than 8 feet),
  • Medium shrub (5-8 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 (Chicago),
  • Zone 6,
  • Zone 7

Soil Preference:

  • Moist, well-drained soil

Acid Soils:

  • Tolerant

Alkaline Soils:

  • Tolerant

Salt Spray:

  • Intolerant

Soil Salt:

  • Intolerant

Drought Conditions:

  • Moderately Tolerant

Poor Drainage:

  • Moderately Tolerant

Season of Interest:

  • Early winter,
  • Mid winter,
  • Late winter,
  • Early spring,
  • Mid spring,
  • Late spring,
  • Early summer,
  • Mid summer,
  • Late summer,
  • Early fall,
  • Mid fall,
  • Late fall

Flower Color & Fragrance:

  • Inconspicuous

Shape or Form:

  • Narrow,
  • Pyramidal,
  • Round,
  • Upright

Growth Rate:

  • Slow

Transplants Well:

  • Yes

Wildlife:

  • Birds,
  • Browsers,
  • Cavity-nesting birds,
  • Small mammals

More Information:

Tree & Plant Care

Foliage often changes color in winter.
Tolerant of alkaline and acid soils.
Best growth in full sun to part shade in well-drained, moist to dry soil.

Disease, pest, and problem resistance

This plant is not favored by deer.
Tolerant of black walnut toxicity.

Native geographic location and habitat

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

Grayish-brown to reddish-brown, with stringy fibers and a network of ridges and shallow furrows.

Leaf or needle arrangement, size, shape, and texture

Flat, spreading horizontal sprays of scale-like evergreen leaves are soft green.

Flower arrangement, shape and size

Inconspicuous, separate male and female flowers.

Fruit, cone, nut, and seed descriptions

Tiny oval cones mature from green to brown.

 

Cultivars and their differences

Deer Proof™ giant arborvitae (Thuja plicata ‘KLMfive’):  A tall, narrow, pyramidal tree, growing 40 to 50 feet high and 15 to 25 feet wide. It is a medium to fast grower with excellent cold hardiness. Loose, narrow habit with horizontal branching.  Dark green foliage has yellow tips. Useful as specimen or hedge or in groupings or screens.  Not favored by deer.

Excelsa giant arborvitae (Thuja plicata ‘Excelsa’):  A pyramidal tree, growing 25 to 35 feet high and 10 to 15 feet wide.  Loose habit with horizontal branching.  Glossy, green foliage turns yellow-green in winter. useful as specimen, hedge, in groupings, or screens.

Green Giant arborvitae (Thuja ‘Green Giant’): A hybrid between T. plicata and T. standishii'.  May grow up to 4o feet tall; maintains good green color in winter.

Hillier giant arborvitae (Thuja plicata ‘Hillieri’):   Spreading form, growing 7 to 10 feet high and wide. The plant’s blue-green foliage turns bronze-brown in winter. Useful as specimen or for hedges, groupings, and screens.

Spring Grove® giant arborvitae (Thuja plicata ‘Grovepli’):  25 feet high by 8 feet wide; considered deer resistant.

Virescens giant arborvitae  (Thuja plicata ‘Virescens’):  A narrow, pyramidal small tree form growing 20 to 30 feet high and 10 to 20 feet wide. Foliage is glossy and bright green year-round. Useful as specimen or for hedges in formal and semi-formal plantings, groupings, and screens.

Location of Thuja plicata (Giant arborvitae) at the Arboretum