How to Grow Western Redcedar
Western Redcedar
Thuja plicata
treeWestern redcedar is a large, fast-growing evergreen conifer native to the Pacific Northwest, reaching heights of 40-200 feet with a narrow, pyramidal form. Despite its common name, it is not a true cedar but rather a member of the cypress family. The foliage is soft, scale-like, and aromatic, with a pleasant, pleasant fragrance when crushed.
When should you plant Western Redcedar in your zone?
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Example Western Redcedar timeline · Pittsburgh, PA (Zone 6b)
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Plant Western Redcedar
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Western Redcedar
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Western Redcedar dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives best in zones 4b-9a; prefers cool, moist maritime climates of the Pacific Northwest
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Get my Western Redcedar timeline →Growth Stages
Seedling/Nursery
1-2 years in nurseryYoung plants 1-3 feet tall with tender foliage and fine root systems
Keep soil consistently moist; protect from strong winds and harsh sun exposure; provide afternoon shade in hot climates; do not allow roots to dry out
Establishment
2-3 years after plantingTrees 3-10 feet tall developing stronger branching structure and deeper root systems
Water deeply and regularly during first 2-3 years; apply 3-4 inches of mulch; avoid drought stress; prune only to remove dead branches; stake if in exposed locations
Juvenile Growth
5-20 years depending on conditionsVigorous upright growth phase, trees 10-40 feet tall, developing dense foliage and conical crown
Maintain consistent moisture; thin competing branches to encourage strong central leader; minimal pruning needed; monitor for pest issues
Mature Growth
50+ years and beyondTree reaching full height (40-200+ feet), developing thick bark and massive trunk; crown remains dense and pyramidal
Minimal maintenance required; occasional removal of dead or diseased branches; maintain adequate moisture during drought years; monitor for interior branch die-off from shading
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Usually minor; prune affected branches if severe; rarely requires treatment; insecticidal spray if populations become heavy
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Maintain tree vigor and proper watering; prune dead branches promptly; no chemical control recommended; native parasitoid wasps provide natural control
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and
(Phytophthora spp., various decay fungi)
Ensure excellent drainage; avoid waterlogging; maintain tree vigor; prune dead branches; do not apply wound dressing as it inhibits natural healing
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More common in hot, dry conditions; increase humidity if possible; spray with water or neem oil if severe; rarely problematic in optimal growing conditions
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Prune infested branches; apply horticultural oil in dormant season; maintain tree vigor; usually self-limiting
Uses
Rot-resistant lumber and shingles
HouseholdThe naturally decay-resistant heartwood is prized for outdoor construction, roofing shingles, siding, and weather-resistant applications. Historically used by Pacific Northwest Indigenous peoples for canoes, longhouses, and totems. [source]
Aromatherapy and fragrance
HouseholdThe foliage has a pleasant, distinctive aromatic scent used in essential oils, incense, and natural fragrances. Crushed foliage releases a soothing cedarwood aroma. [source]
Traditional herbal remedies
MedicinalPacific Northwest Indigenous peoples used leaf tea for respiratory health and cough relief. Contains bioactive compounds including thujone and other volatile oils with antimicrobial and anti-inflammatory properties. [source]
Woodworking and carving
CraftThe soft, easily worked wood is ideal for fine woodworking, hand carving, and sculptural projects. Its fine grain and natural beauty make it popular for both utilitarian and decorative applications. [source]
Habitat for forest wildlife
WildlifeProvides shelter and nesting sites for songbirds, owls, and other forest fauna. Supports complex forest ecosystems with understory plants and small mammals. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Western redcedar is not harvested in the home garden context. In forestry, trees are typically harvested when 40-80+ years old for lumber, shingles, and split products. Wood is decay-resistant and aromatic.
Fun Facts
- 🌱 Western redcedar can live for over 1,000 years, with some specimens exceeding 3,500 years old. Ancient stands in British Columbia are among the oldest living trees in North America.
- 🌱 Pacific Northwest Indigenous peoples (Tlingit, Haida, Kwakwaka'wakw) used nearly every part of the tree—wood for houses and canoes, bark for clothing and baskets, roots for hats—calling it the 'tree of life' for its cultural and practical importance.
- 🌱 The wood contains natural compounds called thujaplicins that make it highly resistant to decay, rot, and insect damage, allowing outdoor structures to last decades or centuries without chemical treatment.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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