Western red cedar
Thuja plicata · Cupressaceae
📷 abdallahh from Montréal, Canada · CC BY 2.0
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around western red cedar and prepare for winter.
ID card
- Scientific name
- Thuja plicata
- Family
- Cupressaceae
- Type
- Evergreen conifer
- Mature height
- Up to 20 m
- Foliage
- Evergreen, aromatic dark green scales
- Growth
- Fast to very fast
- Hardiness
- Very hardy, down to -20 °C
- Origin
- North American Pacific coast
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Western Red Cedar (Thuja plicata) is a giant that hates active lime and heavy soils. Plant it in neutral to slightly acidic, well-draining soil.
The common mistake
Planting it in chalky or overly compacted soil: it yellows, declines slowly, and sometimes dies back without apparent reason.
The pro's trick
Space them generously (minimum 3 m apart) if planting several: poor air circulation encourages fungal decline and bark beetle attacks.
Care
Light exposure
Western red cedar prefers full sun or partial shade. It tolerates light shade well but develops a denser, more branched form in sunlight. Plant it in a location sheltered from strong winds that may damage it.
Watering
Water regularly during the first year after planting to ensure good root establishment. Once established, western red cedar is moderately drought-tolerant but prefers moist to consistently cool soil. Reduce watering in winter.
Soil type
It adapts to most well-drained soils, slightly acidic to neutral. Avoid heavily chalky or compacted soils. Soil rich in organic matter promotes growth. Amend at planting time if needed.
Pruning and maintenance
Pruning is generally not necessary; the pyramidal form develops naturally. Simply remove dead or damaged branches in late winter. If you wish to densify the plant, prune lightly in spring before new growth begins.
Fertilizer
Fertilizer is generally not essential in fertile soil. If growth seems slow, apply balanced fertilizer in spring or early summer. Avoid excess nitrogen, which makes foliage too soft.
Diseases and pests
Relatively robust, it can be affected by fungi in very humid, poorly ventilated conditions. Watch for scale insects or spider mites in dry environments. Good air circulation and optimal drainage prevent most problems.
Did you know?
Western red cedar was sacred to the First Nations of the Pacific coast: they used it to build totems, canoes, and houses. Its highly durable wood, naturally resistant to insects and rot thanks to its essential oils, remains one of the most prized in high-end woodworking.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- Giant sequoiaSequoiadendron giganteum
- JuniperJuniperus communis
- Northern WhitecedarThuja occidentalis
- Bald cypressTaxodium distichum
- Lawson cypressChamaecyparis lawsoniana
- Coast redwoodSequoia sempervirens
Tips generated and checked by Viridia — adapt them to your local climate.