How to Grow Cedar
Thuja plicata
Cedars thrive in full sun to partial shade in well-drained soil. True cedars (Cedrus) are drought-tolerant once established and dislike waterlogged ground. Western Red Cedar (Thuja plicata) tolerates moister conditions and is widely used for hedging. All cedars are long-lived specimen trees with aromatic wood and require minimal pruning — avoid cutting into old bare wood on true cedars as they will not regenerate from it.
Yearly Lifecycle
Care Essentials
Established cedars rarely need feeding. Young trees benefit from a balanced slow-release fertiliser in spring for the first two or three years after planting.
Watch For
- Honey fungus at the base (Armillaria)
- Cedar aphids on young growth
- Phytophthora root rot in poorly drained sites
- Dieback on true cedars from cutting into bare wood
Track your Cedar care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Full sun to partial shade
True cedars prefer full sun for best form. Western Red Cedar hedging tolerates partial shade. All need good light to maintain dense foliage.
💧 Watering
Drought-tolerant once established
Water well for the first 2-3 seasons while roots establish. Mature trees are very drought-tolerant. Hedging may need water during extended dry spells.
🌱 Fertilizing
Rarely needed
Young trees benefit from a slow-release balanced fertiliser in spring for the first 2-3 years. Established trees require no feeding. Over-fertilising can cause soft vulnerable growth.
✂️ Pruning
Minimal; formative pruning in spring only
Never cut into bare wood on true cedars as it will not regenerate. Thuja hedging can be trimmed in spring and late summer. Allow true cedars to develop their natural form.
❄️ Overwintering
Fully hardy once established
Young trees may need stake support in exposed positions for the first 2-3 winters. No other protection needed. Established specimens tolerate severe cold.
Growing Tips
Never cut true cedars into old bare wood
Unlike yew and some other conifers, true cedars (Cedrus) will not regenerate from bare wood. Only trim green growth.
Western Red Cedar suits hedging; true cedars need space
Thuja plicata (Western Red Cedar) makes excellent formal hedging. True cedars (Cedrus libani, deodara, atlantica) are large specimen trees needing 15m+ spread.
Stake young trees for first 2-3 years
Young cedars have relatively sparse root systems. Stake with a low stake and flexible tie to allow trunk movement while roots establish.
Pests & Diseases
Pest Cedar Aphid
Identification: Colonies of small dark aphids on shoots; honeydew and sooty mould on foliage below
- Encourage natural predators; spray with water to dislodge in mild cases
- Apply contact insecticide containing pyrethrins in spring when active
Pest Cedar Adelgid
Identification: White woolly patches on shoots and needles; resembles small tufts of cotton wool
- Spray with plant oil-based winter wash during dormancy; prune out heavily infested shoots
- Apply systemic insecticide in spring when new growth emerges
Disease Honey Fungus Armillaria mellea
Symptoms: Crown dieback; honey-coloured toadstools at base in autumn; white mycelial fans under bark; black bootlace rhizomorphs in soil
Treatment: No cure; remove dead trees and as much root as possible; do not replant with susceptible species
Prevention: Maintain tree vigour; avoid damage to trunk base; physical barriers can slow spread
Disease Phytophthora Root Rot Phytophthora cinnamomi
Symptoms: Progressive crown thinning; foliage yellowing then browning from inside out; dark staining at root collar
Treatment: No reliable cure for large trees; improve drainage; avoid soil compaction over root zone
Prevention: Plant in well-drained soil; avoid waterlogging; do not pile soil or mulch against the trunk
Log Cedar in your garden — track growth, care, and harvests year after year
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