Western red cedar

Western red cedar: how do you recognise it?

Habit

Tree of 25–40 m with a conical crown about 8 m wide and an upright leader; as a hedge usually 1.5–4 m.

Foliage

Scale leaves in flat, slightly drooping sprays; glossy dark green above, with white patches below. Crushed, they smell sweetly of pineapple.

Bark

Reddish-brown, in long, soft, fibrous strips; the base of the trunk is often broadly flared and fluted.

Cones

Upright, elongated cones 1–1.5 cm long with 10–12 scales that open like a small flower.

Difference from northern white cedar

Northern white cedar has dull yellowish-green foliage without white patches that turns brownish in winter, and stays smaller.

Difference from Lawson cypress

Lawson cypress has foliage that smells resinous, with a white X pattern, and round cones.

Pruning: May–June and August–September

Identify by feature: Scales instead of needles

Looks like it, but isn’t

• Northern white cedar Thuja occidentalis: dull yellowish-green foliage without white patches that turns brownish in winter; stays smaller. Difference from northern white cedar
• Lawson cypress Chamaecyparis lawsoniana: foliage that smells resinous, with a white X pattern, and round cones. Difference from Lawson cypress
• Thuja Thuja: the page for the whole genus, with what all thujas have in common.

Why grow it?

• A fast, dense hedge that stays dark green all year round, even in winter.
• Stays dense even in shade, better than the northern white cedar.
• Tolerates pruning better than most conifers.
• Left to grow freely, a stately park tree with a reddish-brown, fibrous trunk.

Western red cedar: where does it grow best?

• Sun, partial shade and even shade: as a hedge it stays fairly dense even next to tall trees.
• Any soil, acid or chalky, that neither dries out nor becomes waterlogged; it likes moist, moisture-retentive soil.
• On dry sandy soil and against a hot south-facing wall it struggles in dry summers.
• Left to grow freely it reaches 25–40 m in height and about 8 m across: only for a park or a very large garden. In an ordinary garden, keep it as a clipped hedge.

Light

Sun to shade

Legal basis

Any garden soil

Moisture

Normal

Size

30 m tall, 8 m wide

Hardiness

Throughout Belgium, no protection needed

Goes well with

• Japanese skimmia: A low, evergreen shrub for the shade in front of the hedge, with fragrant little flowers in spring.
• White dogwood: Red stems in winter that glow against a dark green hedge.
• Witch hazel: Yellow or orange winter flowers that stand out beautifully against the dark green.

Good and bad companions

Goes well with

• Tolerate the shade under this tree: oregon grape, rhododendron, oleaster, japanese skimmia, garden privet, camellia, laurustinus, box-leaved honeysuckle

Best kept away from

• Sun-loving plants get too little light under the dense crown: english lavender, heather, butterfly bush, blackthorn, highbush blueberry, sea buckthorn, japanese rose, broom

Western red cedar: when and how to plant it?

1. Plant root-balled or pot-grown plants in September–October or in March–April.
2. For a hedge: 2–3 plants per metre, depending on size.
3. Dig a wide trench, mix compost into the soil and plant at the same depth as before.
4. Water generously straight away and weekly during dry spells in the first year; a layer of mulch keeps the soil moist.

Care

Watering

Regularly in dry spells during the first two years; later too in long dry summers.

Feeding

A little compost or organic fertiliser along the hedge in March–April.

Height

It grows fast: keep a hedge at the right height from the start, because a hedge that is too tall is hard to bring down later.

Inside

In autumn the oldest scale leaves inside turn brown and drop: that is normal.

Tip: For a hedge in shade, western red cedar is the best thuja. Choose a hedging cultivar such as ‘Atrovirens’: glossy dark green and a good colour even in winter.

Western red cedar: when to prune it?

Pruning months: May–June and August–September.

When: Trim a hedge in May–June and late August, by mid-September at the latest. Check first that no birds are nesting.

How:

• Only cut into the green. It tolerates pruning better than most conifers, but a bare, brown patch fills in slowly, if at all.
• Keep the hedge slightly narrower at the top than at the bottom, and cut back the top as soon as it reaches the height you want.
• A free-standing tree needs no pruning; leave the lower branches.

Caution: Check first that no birds are nesting, and wear gloves: the sap can irritate the skin.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Cuttings

In August–September, pull off a side shoot 10–15 cm long with a heel and root it in cutting compost under glass or in a cold frame.

Layering

Lower branches lying on the ground can take root: peg one down into the soil and cut it free after a year.

Western red cedar: how does it get through the winter?

Hardy throughout Belgium: no protection needed.

• Fully hardy and, unlike the northern white cedar, it stays a good green in winter.
• Shake wet snow off the hedge, or the branches will splay apart.

Diseases and pests

• Drought: Brown patches after a dry summer, especially on sand and against a south-facing wall. Water and mulch; dead sections fill in slowly, if at all.
• Root rot: On wet soil plants turn brown and die (Phytophthora). Only replace them once the drainage has been improved.
• Bare at the base: A hedge that goes bare at the bottom gets too little light there. Trim it narrower at the top than at the bottom.
• Dog urine and road salt: Brown patches at the base of a hedge along the street. Rinse with plenty of water, and plant a new hedge a little further from the pavement.

Through the year

• March: Plant (March–April); compost along the hedge.
• May: First trim (May–June); check first that no birds are nesting.
• June: Trimming still possible; water in dry spells.
• July: Water young hedges in dry spells.
• August: Second trim in late August; take cuttings.
• September: Last trim by mid-September at the latest; planting season begins.
• December: Shake wet snow off the hedge.

What can you use it for?

Garden and landscape

Fast, evergreen hedge that stays dense even in shade; left to grow freely, a large park tree.

Wood

Light, rot-resistant wood (‘western red cedar’) for cladding, shingles, garden sheds and saunas.

Caution: Leaves and twigs are poisonous if eaten, also for livestock. The sawdust can cause allergies.

Did you know?

• The Indigenous peoples of the North American west coast carved their totem poles, houses and canoes from its rot-resistant wood.
• Its light, rot-resistant timber is known as ‘western red cedar’: for cladding, shingles, garden sheds and saunas.
• Lower branches that touch the ground take root: around an old, free-standing tree a ring of new trunks can form this way.