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Thuja occidentalis

Cold-hardy evergreen conifer with dense, aromatic, scale-like foliage in flattened sprays, native to eastern North America and typically growing as a conical to narrow-pyramidal tree, often used for low-maintenance hedges, privacy screens in row plantings, and entranceways.

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Common Names

Northern White Cedar, Arborvitae, American Arborvitae, Eastern White Cedar, White Cedar, Eastern Arborvitae, Swamp Cedar

Summary

Northern white-cedar, also called American arborvitae or eastern arborvitae, is an evergreen conifer native to eastern Canada and the north-central and northeastern United States. It forms a dense, cone- to broad-pyramidal crown with slender, fan-like branches bearing scale-like, aromatic foliage that stays green to yellow-green in winter. The bark is reddish-brown and peels in vertical strips. Small upright cones mature brown. Typical mature size is 20–40 ft tall with a 10–15 ft spread.

Growing conditions include full sun to partial shade and moist, well-drained soil tolerant of clay, loam, and rocky substrates, with pH ranging from neutral to alkaline. Regular watering after planting and deep watering during prolonged drought help establishment. Mulch 2–3 inches, keeping mulch away from the trunk; hedge spacing commonly 3–5 ft for screen plantings. Pruning is minimal and best kept to shape, avoiding cuts into old wood. Pests such as bagworms, spider mites, and arborvitae leafminers may occur, and deer may browse foliage. Practical uses include hedges, privacy screens, windbreaks, foundation plantings, and specimen plantings, with evergreen year-round structure and habitat for wildlife.

Lifecycle

Perennial

Height

20-60 feet

Spread

10-15 feet

Hardiness Zones

Zones 2-7

Sunlight Requirements

Full sun to partial shade.

Soil Type

Moist, well-drained loamy soil with neutral to alkaline pH

Soil Drainage

Moist, well-drained soil; not waterlogged.

Soil pH

Neutral to alkaline soil (pH around 7 or slightly higher)

Bloom Color

Insignificant

Bloom Time

Non-flowering

Foliage Color

Green; foliage color ranges from emerald green and bright green to dark green and gold/yellow-green, with possible bronze or yellow-brown coloration in winter.

Fall Foliage Color

No fall color change; evergreen; green year-round.

Leaf Lifecycle

Evergreen needle

Growth Rate

Slow

Seasons of Interest

Spring, Summer, Fall, Winter

Propagation Methods

Seeds, Layering, Cuttings, Vegetative reproduction

Attracts Wildlife

Attracts birds; nesting sites for songbirds and winter cover

Taxonomy

Taxonomic Rank
Species
Author
L.
Publication
Sp. Pl. 1002. (1753)

Superior Taxa

Kingdom
Plantae
Subkingdom
Pteridobiotina
Phylum
Pinophyta
Class
Pinopsida
Subclass
Cupressidae
Order
Cupressales
Family
Cupressaceae
Genus
Thuja

Synonyms

Juniperus ericoides Retinispora devriesiana Retinispora pygmaea Retinispora dubia Retinispora ellwangeriana Retinispora meldensis Retinispora keteleeri Retinispora troubetzkoyana Thuja globosa Thuja ericoides Thuja ellwangeriana Thuja nana Thuja obtusa Thuja minor Thuja devriesiana Thuja caucasica Thuja compacta Thuja occidentalis var. cristata Thuja vervaeneana Thuja tatarica Thuja recurvata Thuja procera Thuja recurva Thuja sibirica Thuja occidentalis f. gaspensis Thuja occidentalis f. prostrata Thuja theophrasti Chamaecyparis boursieri Cupressus arborvitae Thuja occidentalis var. pendula Thuja occidentalis f. pendula Thuja occidentalis f. pendula-glauca Thuja occidentalis var. alba Thuja occidentalis f. alba Thuja occidentalis var. variegata Thuja occidentalis f. variegata Thuja occidentalis f. vervaeneana Thuja occidentalis f. filiformis Thuja occidentalis var. aureovariegata Thuja occidentalis f. aureovariegata Thuja occidentalis f. wareana-lutescens Thuja occidentalis var. variegata-aurea Thuja occidentalis var. aurea Thuja occidentalis f. aurea Thuja occidentalis f. sempervirens Thuja occidentalis var. lutea Thuja occidentalis f. lutea Thuja occidentalis var. robusta Thuja occidentalis f. robusta Thuja occidentalis f. viridis Thuja occidentalis var. rosenthalii Thuja occidentalis f. rosenthalii Thuja occidentalis var. douglasii-pyramidalis Thuja occidentalis f. filicoides Thuja occidentalis f. magnifica Thuja occidentalis var. compacta Thuja occidentalis f. compacta Thuja occidentalis var. buchananii Thuja occidentalis var. fastigiata Thuja occidentalis f. fastigiata Thuja occidentalis var. plicata Thuja occidentalis f. mastersii Thuja occidentalis var. globosa Thuja occidentalis f. globosa Thuja occidentalis f. woodwardii Thuja occidentalis var. hoveyi Thuja occidentalis f. hoveyi Thuja occidentalis f. pumila Thuja occidentalis var. umbraculifera Thuja sibirica var. pendula Thuja occidentalis var. filiformis Thuja occidentalis f. ohlendorffii Thuja occidentalis f. cristata Thuja occidentalis f. ericoides Thuja occidentalis f. ellwangeriana Thuja occidentalis f. occidentalis Retinispora nobleana Retinispora glaucescens Thuja hoveyi Thuja odorata Thuja canadensis Thuja bodmeri Thuja variegata Thuja occidentalis var. douglasii Cupressus nobleana Thuja occidentalis var. sempervirens Thuja occidentalis var. vervaeneana Thuja occidentalis f. riversii Thuja occidentalis var. magnifica Thuja occidentalis f. buchananii Thuja occidentalis var. woodwardii Thuja occidentalis f. umbraculifera

References

Arborvitae Growing Guide: Care, Types & Planting T…. provenwinners.com.
American Arborvitae (Thuja occidentalis): Facts & …. americangardener.net.
Conifer Database - occidentalis. conifersociety.org.
Thuja occidentalis: White Cedar. edis.ifas.ufl.edu.
Thuja occidentalis. en.wikipedia.org.
Thuja Occidentalis Guide: How to Grow & Care for “…. gardenbeast.com.
Thuja occidentalis | Landscape Plants | Oregon Sta…. landscapeplants.oregonstate.edu.
Home - Arborvitae (Thuja) - Research Guides at New…. libguides.nybg.org.
Caring for Your Thuja occidentalis: A Guide to Mai…. northernridgenursery.com.
Thuja occidentalis. plantfacts.osu.edu.
American Arborvitae - Thuja occidentalis | North C…. plants.ces.ncsu.edu.
Thuja occidentalis L. | Plants of the World Online…. powo.science.kew.org.
NORTHERN WHITE-CEDAR - THUJA OCCIDENTALIS. trees.umn.edu.
Thuja occidentalis: Origins, Cultivars, Landscape …. verdantlandscaping.ca.
Thuja occidentalis | Care, watering and pruning gu…. viverosgonzalez.es.
How To Grow Thuja Occidentalis {My Best Tips} - Ja…. gardendad.co.uk.
Northern White-cedar, Arborvitae (Thuja occidental…. gardenershq.com.
How To Take Care Of Thuja Occidentalis. gardenguides.com.
Thuja occidentalis - Plant Finder. missouribotanicalgarden.org.
Thuja occidentalis L - Southern Research Station -…. srs.fs.usda.gov.
World Flora Online. worldfloraonline.org. June 2024.