Can western redcedar be grown successfully in containers?

Container growing is possible for young plants or dwarf cultivars. Use a deep, heavy pot to prevent tipping and allow root depth. Expect slower growth and plan to transplant into the ground once roots fill the container.

Is western redcedar suitable for indoor decoration or year-round indoor growing?

This conifer is not suitable for long-term indoor culture. Indoor air is too dry and low in light, so foliage declines over time. Western redcedar indoor care works only as a very short-term, temporary display.

western redcedar Care (Thuja plicata)

Also known as: Canoe Cedar, Giant Arbor-vitae, Pacific Red-cedar, Giant Cedar, Shinglewood, Western or Giant Arborvitae, shingle cedar

About western redcedar

Western redcedar, Thuja plicata, is a long-lived coniferous tree known for its aromatic, rot-resistant wood and dense, scale-like foliage. It is commonly used in hedges, windbreaks, and screens, as well as in forestry and timber production.

In nature, it occurs along the Pacific Northwest of North America, often in moist forests and near streams. The tree forms a tall, narrow to broadly conical crown with flattened sprays of rich green foliage.

Its preference for cool, moist conditions and relatively tolerant nature makes it manageable for many gardeners, though it eventually becomes very large. Understanding how to care for western redcedar starts with providing consistent moisture, good drainage, and protection from very hot, dry conditions.

Main Plant Requirements

Care Difficulty

Moderate Care

Light Preference

Full Sun

Water Requirements

Regular Water

Temperature Preference

Cold Hardy

Hardiness Zone

5–7

Soil Texture

Loamy, Clay, Organic-rich

Soil pH

Acidic (5.5–6.5), Slightly acidic (6.5–7.0)

Soil Drainage

Moist but well-drained

Fertilization

Minimal (feed rarely)

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How to Care for the western redcedar

Thuja plicata grows best with consistent outdoor light suited to its native forest edge habitats.

Provide 4–6 hours of direct sun daily, ideally with morning sun and light afternoon shade, especially in hotter regions.
Tolerates partial shade (as low as 2–3 hours direct sun) but may grow more open and less dense, especially on shaded sides.
Avoid intense, all-day summer sun in hot, dry climates, which can cause foliage scorch; young western redcedar benefits from temporary shade screens in the first 1–2 summers.

Thuja plicata prefers evenly moist, well-drained soil and does not tolerate prolonged drought or standing water.

For new plantings, water when the top 3–5 cm of soil feels dry, aiming for a deep soak that moistens 20–30 cm down.
In the first 1–2 years, increase watering during hot, dry periods and reduce during cool, rainy seasons, always checking soil before watering.
Signs of overwatering include yellowing tips and soft, dark roots, while dry, browning foliage and twig dieback suggest underwatering or prolonged drought.

This species is a cold-hardy conifer adapted to cool, moist climates with moderate summers.

Ideal growing temperatures are about 50–75°F (10–24°C), with best vigor in regions that stay relatively cool and humid.
Mature plants tolerate winter lows near -20°F (-29°C) once established, but newly planted trees need protection from drying winter winds.
Thuja plicata handles short heat spells up to about 90°F (32°C) if soil moisture is maintained, but prolonged heat and dry wind can cause leaf scorch and tip dieback.

Thuja plicata tolerates a wide humidity range and rarely needs special humidity management outdoors.

Thuja plicata grows best in deep, moist, well-aerated mineral soil with reliable drainage.

Aim for a loamy or sandy-loam structure with moderate organic matter to hold moisture without becoming heavy.
Keep soil consistently moist but not waterlogged; drainage should allow water to clear the root zone within a few hours after rain or irrigation.
Target a slightly acidic to neutral pH, around 6.0–7.0, amending alkaline ground with composted bark or peat-based material.
On compacted or clay sites, improve aeration and drainage by incorporating coarse sand or fine gravel into the top 20–30 cm before planting.

This species can be grown in large outdoor containers, mainly for young plants or dwarf cultivars.

Select a tall, heavy container that resists tipping as the tree becomes more top-heavy in wind exposure.
Use a deep, bark-based mix that holds moisture yet drains quickly to prevent chronic saturation around the woody roots.
Raise the container on feet or pavers so drainage holes stay clear and excess water does not pool under the pot.

Thuja plicata usually needs modest feeding, especially when young or grown in poor soil.

Use a balanced slow-release granular fertilizer (for example 10-10-10) or well-rotted compost in early spring.
Apply a light dose once per year during the growing season; avoid repeated heavy applications.
Reduce or skip feeding in winter when growth is dormant to prevent soft, frost-sensitive shoots.
Water thoroughly after applying fertilizer and avoid high-strength products near dry roots to limit burn.

Thuja plicata responds well to light, careful pruning that maintains its natural form.

Carry out structural pruning in late winter or very early spring before active growth starts.
Remove dead, diseased, storm-damaged, or crossing branches first to improve health and airflow.
Shear only the outer green tips, never cutting back into bare brown wood that will not reshoot.
Use clean, sharp hand pruners or hedge shears, creating a slightly tapered shape wider at the base.

Western redcedar is usually grown in the ground, so focus on careful transplanting rather than frequent repotting.

Transplant in late fall or early spring when soil is workable and air temperatures are cool.
Look for slow growth, circling roots, or a root-bound container as signs a young plant needs a larger space.
Dig a wide, shallow planting hole, keep the root ball intact, and set the root flare level with the soil surface.
Water deeply after planting, mulch 5–8 cm around (not against) the trunk, and keep soil evenly moist while roots establish.

Thuja plicata is most often propagated from cuttings to maintain desired characteristics.

Take semi-ripe cuttings in late summer or early fall, selecting healthy, pencil-thick shoots.
Remove lower foliage, keep a short heel of older wood if possible, and dip the base in rooting hormone.
Insert cuttings into a free-draining mix, then keep in bright, indirect light with consistently moist but not waterlogged media.
Seed propagation is possible but slower; cold stratification improves germination for stored seed.

Mature Thuja plicata is generally cold hardy and needs limited winter care in most temperate climates.

Apply 5–8 cm of organic mulch over the root zone in late fall, keeping it slightly away from the trunk.
Water well before the ground freezes, especially for newly planted or container-grown trees.
For young plants in windy or exposed sites, use burlap screens to reduce desiccating winter winds.

Overwatering

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Care Tips

Windbreak establishment

Stake young trees in exposed sites for the first 1–2 years and install a windbreak fence or plant in staggered rows to reduce desiccating winter winds that can brown foliage on the windward side.

Mulch root zone

Apply a wide, 5–8 cm deep ring of coarse bark mulch out to the drip line, keeping it 5–8 cm away from the trunk, to stabilize soil moisture, reduce competition from turf, and protect shallow feeder roots from heat and frost.

Snow load management

In regions with heavy wet snow, loosely tie the main leaders and upright branches together with soft horticultural tape each late fall to prevent splitting or permanent splaying under snow and ice loads.

Salt exposure protection

Where road salt or de-icing products are used, site plants at least 3–4 m back from treated pavements, build a low berm, or use burlap screens in winter to reduce salt spray that can burn foliage and stunt growth.

Root collar inspection

Once a year gently pull back mulch and soil at the base to ensure the root flare is visible above grade, correcting any excess soil or mulch that could lead to bark rot and decline when caring for western redcedar.

Common Pests and Diseases

Cedar leaf blight

This disease causes browning, dieback, and shedding of foliage, often starting on lower inner branches in spring and early summer. Symptoms include scattered dead branch tips and thin, uneven foliage, especially in dense, shaded, or damp plantings.

Solution

Prune out and destroy infected twigs during dry weather, thinning the canopy to improve airflow and light penetration. Avoid overhead watering, space plants adequately, and, in severe or recurrent cases, use a labeled copper or chlorothalonil fungicide in early spring when new growth emerges, following local Thuja plicata care instructions.

Kabatina twig blight

This disease causes small, discolored twig tips that turn dull brown or gray, often with a sharp line between healthy green tissue and dead sections. Symptoms include scattered tip dieback on young shoots, usually noticeable in late winter or early spring.

Solution

Cut back infected twig tips 10–15 cm into healthy wood and remove fallen debris from around the base to reduce spores. Improve plant vigor with proper watering and mulch, avoid shearing during wet conditions, and, if needed, protect new growth with a labeled fungicide applied in late winter or very early spring in areas where the disease is persistent.

Cedar bark beetles

These insects bore into the bark and cambium, causing branch dieback, off-color foliage, and sometimes pitch tubes or fine boring dust on trunks and larger branches. This pest is more common on stressed trees, especially those exposed to drought, root damage, or mechanical injury.

Solution

Prune and dispose of infested branches to remove beetle galleries and avoid leaving cut Thuja wood or piles of brush nearby that attract new beetles. Keep trees healthy with regular deep watering during dry periods, prevent trunk injury, and consult a certified arborist about timely trunk or bark-spray treatments with a labeled insecticide where infestations are heavy and recurrent.

Bagworms

These insects create spindle-shaped, hanging bags made of foliage and silk, and heavy infestations lead to noticeable defoliation and bare branch tips. This pest can severely thin the canopy of young or small trees if not removed early.

Solution

Hand-pick and destroy bags during fall, winter, and early spring before larvae emerge, focusing on the inner canopy and higher branches if safely reachable. For active caterpillars on small or moderate infestations, use a Bacillus thuringiensis (Bt) or spinosad spray directed at the foliage, following label directions and treating when larvae are small and actively feeding.

Phytophthora root and collar rot

This disease affects roots and the lower trunk in poorly drained or chronically wet soils, leading to dull, off-green foliage, overall decline, and dieback from the top down. Symptoms include poor new growth and sometimes dark, sunken, or resinous areas around the root collar at soil level.

Solution

Improve drainage by redirecting water, adjusting grade, or relocating plants away from persistently wet spots, and avoid overwatering or heavy mulch piled against the trunk. Remove and discard severely affected plants with most roots decayed, and in high-value landscape settings consider consulting a plant health professional about soil drenches with labeled phosphonate fungicides to protect remaining or replacement trees in sites with a known Phytophthora history.

Interesting Facts

Naturally decay-resistant wood

The heartwood contains aromatic compounds that make it very resistant to fungal decay and insect damage, which is why it has been widely used for outdoor structures such as shingles, poles, and traditional canoes.

Shallow but wide roots

This species forms a very wide, shallow root system instead of a deep taproot, allowing efficient uptake of surface moisture but also making mature trees more vulnerable to windthrow in saturated soils.

Important canopy nurse tree

In Pacific Northwest forests, western redcedar often acts as a nurse tree, creating cool, moist, low-light conditions under its canopy that help shade-tolerant species such as western hemlock seedlings establish and grow.

Did you know?

Large, old western redcedar trees can develop huge, fluted trunks and hollow basal chambers that provide important shelter for wildlife and, in Indigenous cultures of the Pacific Northwest, have historically been used as living shelters and storage spaces without felling the entire tree.

FAQs about western redcedar

Growth rate is usually moderate to fast, about 30–60 cm per year under good conditions. Rate slows in poor soil, compacted sites, heavy shade, or drought. Young trees often grow faster than mature specimens.