How to Grow Western Red Cedar Emerald Green

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Western Red Cedar Emerald Green

Thuja plicata 'Emerald Green'

tree

Emerald Green is a narrow, columnar cultivar of Western Red Cedar prized for ornamental screening and privacy hedges. It maintains a vibrant emerald-green foliage year-round and grows in a tight, dense form without excessive pruning. This evergreen conifer is ideal for windbreaks, hedges, and formal landscape designs.

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Example Western Red Cedar Emerald Green timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Western Red Cedar Emerald Green

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Western Red Cedar Emerald Green

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact Western Red Cedar Emerald Green dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to partial shade; needs 4+ hours of direct sunlight daily for best color and density
💧
Water: Keep soil consistently moist but not waterlogged; especially important during establishment (first 2 years) and in dry summers; avoid drought stress
📏
Spacing: 24-36 inches center-to-center for hedging; up to 48 inches for specimen plants inches
📅
Days to maturity: Not applicable for trees; reaches functional landscape height in 3-5 years
🌱
Planting depth: Plant at same depth as root ball; top of root ball should be level with ground; do not bury stem

Soil

Type: Well-draining moist soil; tolerates clay and loamy soils
pH: 5.5-7.5
Amendments:
Compost at planting Peat moss or coconut coir for moisture retention Aged bark mulch

Growing Zones

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Thrives in zones 4-8; most vigorous in zones 5-7

4a 4b 5a 5b 6a 6b 7a 7b 8a

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Growth Stages

1

Establishment

Year 1

Young sapling with small root system and initial branching; foliage is bright green but sparse

Water deeply 2-3 times per week; avoid transplanting shock; stake if needed in windy locations; apply 2-3 inches of mulch around base

2

Vegetative Growth

Years 2-4

Rapid upright growth; lateral branches fill in to create denser column; foliage becomes richer emerald color

Maintain consistent moisture; prune only to remove crossing or damaged branches; light shaping in late winter if desired; fertilize lightly in spring

3

Structural Development

Years 5-10

Plant reaches near-mature form; columnar shape fully defined; dense branching throughout

Reduce watering frequency once established; hedge trimming in early summer and again in late summer if tight form desired; minimal fertilizer needed

4

Mature

Year 10 onward

Full-sized specimen 40-60 feet tall and 3-6 feet wide; dense, vibrant emerald-green foliage

Water during extended dry periods (once per week); light pruning for shape maintenance; monitor for scale insects or spider mites in stressed conditions

5

Decline Management

Year 50+

After 50+ years, some interior browning or thinning may occur; outer foliage remains healthy

Avoid excessive pruning into brown wood; ensure adequate water; remove dead branches selectively; generally long-lived (100+ years possible)

Companion Planting

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Plant with:

Avoid planting near:

Black Walnut (allelopathic compound juglone) Dense competing trees that shade heavily Areas with poor drainage and standing water De-icing salt spray zones (plant 20+ feet from roads)

Common Pests

  • Hand-pick bags in dormant season; spray with Bt (Bacillus thuringiensis) in June when crawlers active; prune affected branches

  • Spray foliage with strong water stream to dislodge; use miticide if severe; improve air circulation; avoid high heat stress

  • Prune out affected branch tips; apply spinosad or neem oil in early summer during leaf miner activity; generally minor damage

  • Spray dormant oil in late winter; use insecticidal soap or horticultural oil in spring; prune severely infested branches

  • Ensure excellent drainage; avoid overwatering; improve soil aeration; remove affected trees; plant in raised beds if wet site

Uses

🏠

Privacy Screening & Hedging

Household

Emerald Green's narrow columnar form and dense branching make it ideal for creating windbreaks, privacy screens, and formal hedges. Maintains vibrant foliage in winter when deciduous plants are bare. [source]

🏠

Ornamental Landscaping

Household

The striking emerald-green color and architectural vertical form add visual interest and structure to gardens, foundations, and formal designs. Works well in rows, as accents, or in groupings. [source]

🦋

Wildlife Habitat

Wildlife

Provides shelter, nesting cover, and protection for birds and small mammals. The dense foliage offers refuge in winter and nesting sites during breeding season. [source]

🍳

Aromatic Essential Oil

Culinary

Western Red Cedar foliage contains aromatic oils traditionally used in cedar chest liners and as a fragrance source. The scent has mild insect-repellent properties. [source]

🎨

Natural Craft & Fragrance

Craft

Dried foliage and branches can be used in craft projects, wreaths, and dried arrangements. Aromatic properties make it useful for sachets and natural fragrance applications. [source]

Harvest Tips

Not a harvesting plant; grown for ornamental foliage. Cuttings can be taken for propagation in late summer (softwood) or winter (hardwood) with rooting hormone and mist system.

Fun Facts

  • 🌱 Despite being called 'Western Red Cedar,' it is not a true cedar (Cedrus) but rather a member of the cypress family (Cupressaceae); 'red' refers to the reddish-brown heartwood
  • 🌱 Emerald Green is native to the Pacific Northwest and has been cultivated for thousands of years by Indigenous peoples for canoes, totem poles, and roofing shingles due to its rot-resistant wood
  • 🌱 A single mature Western Red Cedar can live over 1,000 years in its native habitat, making it one of the longest-lived trees in North America

Gardening Terms

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