Northern white cedar (arborvitae) Thuja occidentalis
Northern white cedar (arborvitae) (Thuja occidentalis) is an evergreen perennial tree in the Cupressaceae family, native to Northeastern North America. It grows 6–12 m (20–39 ft) tall and 2–4 m (6.6–13 ft) wide, wants full sun and moderate water, and is hardy to about -40 °C (-40 °F). Space plants about 1.5 m (4.9 ft) apart.
Plan Northern white cedar (arborvitae) in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Northern white cedar (arborvitae) at a glance
| Type | Perennial tree, evergreen |
|---|---|
| Family | Cupressaceae |
| Mature height | 6–12 m (20–39 ft) |
| Mature spread | 2–4 m (6.6–13 ft) |
| Spacing | 1.5 m (4.9 ft) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance moderate |
| Soil pH | 6–8 |
| Cold hardiness | About -40 °C (-40 °F) once established (roughly USDA zone 3) |
| Heat stress | Likely above about 32 °C (90 °F) |
| Flowering | from about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | None |
| Edible | Not grown as food |
| Native to | Northeastern North America |
| Common in gardens of | 🇺🇸 United States, 🇷🇺 Russia, 🇩🇪 Germany |
Is Northern white cedar (arborvitae) toxic?
- People: moderately toxic
- Cats: mildly toxic
- Dogs: mildly toxic
- Parts: foliage, essential oil
Foliage contains thujone, which is toxic in quantity; pets may get mild stomach upset.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Northern white cedar (arborvitae)
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
Questions about Northern white cedar (arborvitae)
- How far apart should I plant Northern white cedar (arborvitae)?
- About 1.5 m (4.9 ft) apart, centre to centre. A mature plant spreads 2–4 m (6.6–13 ft).
- Does Northern white cedar (arborvitae) need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does Northern white cedar (arborvitae) need?
- Moderate water. Drought tolerance is low and waterlogging tolerance moderate.
- How cold-hardy is Northern white cedar (arborvitae)?
- It tolerates about -40 °C (-40 °F) once established, roughly USDA zone 3.
- When does Northern white cedar (arborvitae) flower?
- From about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Northern white cedar (arborvitae) poisonous to cats and dogs?
- For cats it is mildly toxic; for dogs mildly toxic; for people moderately toxic. Foliage contains thujone, which is toxic in quantity; pets may get mild stomach upset.
- What grows well with Northern white cedar (arborvitae)?
- There is no well-documented companion pairing for Northern white cedar (arborvitae). Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- USDA PLANTS Database, USDA NRCS
- University extension gardening guides (general), Various land-grant university extensions
Notes and assumptions
- Widely used for screening hedges planted 1-1.5 m apart; heavily browsed by deer and prone to winter burn in exposed sites.
- Spacing given is for a hedge; specimen trees need 2-3 m.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Creeping juniper Juniperus horizontalis
- Leyland cypress x Cuprocyparis leylandii
- Hinoki cypress Chamaecyparis obtusa
- Dawn redwood Metasequoia glyptostroboides
- Bald cypress Taxodium distichum
- Eastern red cedar Juniperus virginiana
- Common juniper Juniperus communis
- Coast redwood Sequoia sempervirens