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Thuja occidentalis

Phonetic Spelling
THU-ya ock-sih-den-TAH-liss
Description

American Arborvitae is a dense pyramidal-shaped evergreen tree in the Cupressaceae (cypress) family that is native to eastern and central Canada and the eastern and north central portions of the United States. A distinctive feature of this tree is its dominant trunk. The leaves are scale-like and appear dark green on the upper surface and paler below. In the winter month, the leaves appear bronze colored. The bark is grayish brown to reddish-brown with shallow furrows. Small oblong cones appear in the spring, mature to a brown color in the summer, and may be persistent. 

The genus name, Thuja, is the Greek name for a kind of juniper. The species epithet, occidentalsis, means from the Western world.

It is a low-maintenance plant that tolerates clay soil, wet sites, black walnut, and air pollution.  It grows best in moist, neutral to alkaline, well-drained loams.  It does not tolerate dry sites, and exposed windy sites should be avoided.  Also, avoid full shade, or foliage will thin out dramatically.  This tree does best in areas with high atmospheric moisture and in soil with high moisture content.

Cultivars are typically globular, pyramidal, columnar to conical in growth form.

These trees are utilized as specimens, accents, hedges, foundation plants, and for a windbreak. They are easily transplanted. 

Seasons of Interest:

Bark:  Year-round          Foliage:  Year-round          Fruit:  Summer to Year-round

Quick ID Hints:

  • dominate trunk, exfoliating grayish brown to reddish brown with shallow furrows
  • dense, pyramidal habit
  • evergreen gymnosperm
  • branch sprays in flat planes
  • leaves scale-like with blister-like, pustular gland, darker green on the upper surface and paler beneath
  • leaves bronze in winter
  • small light brown cones that are yellow when immature

Insects, Diseases, and Other Plant Problems: Damage from deer browsing can be a serious problem. Leaf miners may damage leaf tips.  Bagworms, mealybug, scales, and spider mites are occasional visitors.  Canker can occasionally be a problem. It does not perform well in overly shady, dry, or windy sites.  It is susceptible to damage including stem breakage in winter from ice and snow accumulations.  The foliage can become winter burned (yellow-brown) in dry, exposed sites.

 VIDEO created by Grant L. Thompson for “Trees, Shrubs, and Woody Vines for Landscaping” a plant identification course offered by the Department of Horticulture at Iowa State University.

More information on Thuja.

Profile Video:
See this plant in the following landscapes:
Courtyard Garden Foundation Planting- West Side of House Michael McCarthy Memorial Garden, All Saints Episcopal, Concord Storage Cottage Mountain Ridge Top Garden - North Woods
Cultivars / Varieties:
'Aurea Nana', 'DeGroots Spire', 'Emerald Green', 'Europe Gold', 'Filiformis', 'Golden Ball', 'Golden Globe', 'Hetz's Midget', 'Hetz's Winter Green', 'Holmstrup', 'Linesville', 'Little Gem', 'Nigra', 'Pendula', 'Pumilia Sudworth', 'Pyramidalis Compacta', 'Rheingold', Sienna Sunset™, 'Smaragd', 'Smart Guard', 'Spudwellii' , 'Sunkist', 'Techny'
Tags:
#cultivars#fragrant#evergreen#conical#interesting bark#specimen#wildlife plant#large tree#native tree#fragrant leaves#medicinal#cover plant#low maintenance#air pollution tolerant#food source wildlife#cpp#NC native#children's garden#foundation planting#playground plant#screening#Braham Arboretum#fantz#nesting sites#food source summer#dendrology#exfoliating bark#food source herbage#coastal UPL#Piedmont Mountains FACW#wet soils tolerant#clay soils tolerant#bird friendly#food source hard mast fruit#black walnut toxicity tolerant#Audubon#mccarthy memorial garden#landscape plant sleuths course
 
Cultivars / Varieties:
'Aurea Nana', 'DeGroots Spire', 'Emerald Green', 'Europe Gold', 'Filiformis', 'Golden Ball', 'Golden Globe', 'Hetz's Midget', 'Hetz's Winter Green', 'Holmstrup', 'Linesville', 'Little Gem', 'Nigra', 'Pendula', 'Pumilia Sudworth', 'Pyramidalis Compacta', 'Rheingold', Sienna Sunset™, 'Smaragd', 'Smart Guard', 'Spudwellii' , 'Sunkist', 'Techny'
Tags:
#cultivars#fragrant#evergreen#conical#interesting bark#specimen#wildlife plant#large tree#native tree#fragrant leaves#medicinal#cover plant#low maintenance#air pollution tolerant#food source wildlife#cpp#NC native#children's garden#foundation planting#playground plant#screening#Braham Arboretum#fantz#nesting sites#food source summer#dendrology#exfoliating bark#food source herbage#coastal UPL#Piedmont Mountains FACW#wet soils tolerant#clay soils tolerant#bird friendly#food source hard mast fruit#black walnut toxicity tolerant#Audubon#mccarthy memorial garden#landscape plant sleuths course
  • Attributes:
    Genus:
    Thuja
    Species:
    occidentalis
    Family:
    Cupressaceae
    Uses (Ethnobotany):
    The essential oils from this plant have been used in cleaners, insecticides, soaps, room sprays and hair care products. The young, inner bark of the new stems is known to have been used to make soup by the Ojibwa tribe. The wood is used in fencing and posts, cabin logs, lumber, poles, shingles, paneling, piling, lagging, pails, potato barrels, tubs, ties, boats, tanks, woodenware. Twigs have been used in some teas for relief of constipation and headache.
    Life Cycle:
    Woody
    Country Or Region Of Origin:
    Central & E. Canada to N. Central and Eastern North America
    Distribution:
    SC west to TN north through IL, IO, Minnesota and Manitoba east to Nova Scotia.
    Wildlife Value:
    Northern white cedar provides nesting sites for songbirds, as well as cover, especially in the winter, for white-tailed deer, which both feed on the branches and use them for shelter from the cold.
    Play Value:
    Fragrance
    Screening
    Wildlife Cover/Habitat
    Wildlife Nesting
    Wind Break
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Tolerates clay soil, wet sites, black walnut and air pollution.
    Dimensions:
    Height: 40 ft. 0 in. - 60 ft. 0 in.
    Width: 10 ft. 0 in. - 15 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Tree
    Woody Plant Leaf Characteristics:
    Needled Evergreen
    Habit/Form:
    Dense
    Pyramidal
    Growth Rate:
    Slow
    Maintenance:
    Low
    Texture:
    Fine
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    Loam (Silt)
    Soil pH:
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Available Space To Plant:
    24-60 feet
    NC Region:
    Mountains
    USDA Plant Hardiness Zone:
    3a, 3b, 4b, 4a, 5a, 5b, 6a, 6b, 7b, 7a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Summer
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    The fruit is an oblong light brown cone that measures 1/3 to 1/2 inches long that appears yellow when young.
  • Flowers:
    Flower Description:
    Conifer, non-flowering.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Needled Evergreen
    Leaf Color:
    Gold/Yellow
    Gray/Silver
    Green
    Leaf Feel:
    Slippery
    Leaf Value To Gardener:
    Fragrant
    Showy
    Leaf Type:
    Needles
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Ovate
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    < 1 inch
    Leaf Width:
    < 1 inch
    Leaf Description:
    Leaves are scale-like in adults, ovate, obtuse to bluntly acute, yellowish green to grayish green below bearing a pustular gland near the apex, appressed to branchlets in opposite pairs, each pair overlapping the adjacent pair above. The scale-like leaves are darker green on the upper surface and paler below, and they appear bronze colored during the winter months.
  • Bark:
    Bark Color:
    Dark Brown
    Light Brown
    Light Gray
    Red/Burgundy
    Surface/Attachment:
    Exfoliating
    Furrowed
    Bark Description:
    The attractive grayish brown to reddish-brown bark has shallow furrows. On mature trees, the bark exfoliates on the branches and trunks. A distinctive feature of this tree is its dominant trunk.
  • Stem:
    Stem Color:
    Brown/Copper
    Green
    Stem Is Aromatic:
    No
    Stem Description:
    The stems are thin and green to brown. They are resistant to breakage.
  • Landscape:
    Landscape Location:
    Recreational Play Area
    Landscape Theme:
    Native Garden
    Winter Garden
    Design Feature:
    Foundation Planting
    Hedge
    Screen/Privacy
    Specimen
    Attracts:
    Small Mammals
    Songbirds
    Resistance To Challenges:
    Black Walnut
    Pollution
    Wet Soil