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TREES & Plants

Giant arborvitae

Western 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, western arborvitaes 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.
 

Botanical name: 
Thuja plicata
All Common Names: 
Giant arborvitae, Western Arborvitae
Family (English): 
Cypress
Family (Botanic): 
Cupressaceae
Tree or Plant Type: 
  • Tree
Foliage: 
  • Evergreen (foliage year-round)
Native Locale: 
  • North America
Hardiness Zones: 
  • Zone 5
  • Zone 6
  • Zone 7
Growth Rate: 
  • Slow
  • Medium
Light Exposure: 
  • Full sun (6 hrs direct light daily)
  • Partial sun (4-6 hrs light daily)
Tolerances: 
  • Alkaline soil
Soil Preference: 
  • Moist, well-drained soil
Flower Color & Fragrance: 
  • Inconspicuous
Size Range: 
  • Large tree (more than 40 feet)
  • Medium tree (25-40 feet)
  • Small tree (15-25 feet)
  • Medium shrub (5-8 feet)
Shape or Form: 
  • Narrow
  • Pyramidal
Landscape Uses: 
  • Specimen
  • Hedge
  • Screen
Time of Year: 
  • Early winter
  • Mid winter
  • Late winter
  • Early spring
  • Mid spring
  • Late spring
  • Early summer
  • Mid summer
  • Late summer
  • Early fall
  • Mid fall
  • Late fall
More Information: 

Size

50 to 70 feet high and 15 to 25 feet wide; usually smaller in cultivation.

Cultivars have been selected in a variety of sizes and shapes.

 

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, pests, and problems

 

Disease, pest, and problem resistance

This plant is not favored by deer.

 

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.

 

Attracts birds, pollinators, or wildlife

These plants cones are appealing to birds such as the cardinal, grosbeak, chickadee, robin and sparrow.  The birds also use the tree for shelter and as a nesting site. 

 

Leaf or needle arrangement, size, shape, and texture

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

 

Fruit, cone, nut, and seed descriptions

Tiny oval cones mature from green to brown.

 

Cultivars and their differences 

 

Deer Proof™ (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' (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.

'Hillieri' (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.

'Virescens' (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.