How to Grow Western Red Cedar 'Emerald Green'

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Western Red Cedar 'Emerald Green'

Thuja plicata 'Emerald Green'

tree

A narrow, columnar evergreen conifer prized for its vibrant emerald-green foliage year-round. 'Emerald Green' is a cultivar of western red cedar that grows in a tight, vertical form, making it ideal for screening, windbreaks, and ornamental landscapes. This dense, low-maintenance tree retains its color even in cold winters.

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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; 6+ hours of direct sun daily for best color and density
💧
Water: Moderate watering, especially during establishment (first 2 years). Prefers consistently moist but not waterlogged soil. Drought-tolerant once established, but performs better with regular moisture. Reduce watering in winter dormancy.
📏
Spacing: 36-48 inches apart (3-4 feet) for screening purposes; wider for specimen trees inches
📅
Days to maturity: 3-5 years to reach functional screening height; 15-20 years to mature size
🌱
Planting depth: Plant at same depth as root ball; top of root ball should be level with ground

Soil

Type: Well-draining loamy or sandy soil; tolerates clay if drainage is improved
pH: 6.0-7.5
Amendments:
Peat moss Compost Perlite or coarse sand for drainage improvement

Growing Zones

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Zones 3-7 are optimal; can tolerate zones 2-8 with proper care

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a

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Growth Stages

1

Establishment

First 12-18 months

Young tree with developing root system, compact foliage, and green coloring. Height 2-4 feet.

Water regularly (1-2 times weekly). Mulch to retain moisture and suppress weeds. Avoid transplant shock by planting in spring or early fall. Protect from strong winds.

2

Active Growth

Years 2-8

Rapid vertical growth phase with dense branching and columnar form becoming prominent. Height 4-15 feet.

Maintain consistent moisture. Prune lightly to shape if needed in early spring. Fertilize annually with balanced slow-release fertilizer in spring.

3

Mature Form

Years 8-15+

Tree reaches full height and width; dense emerald-green foliage throughout. Height 40-60 feet, width 3-6 feet.

Reduce watering frequency as tree is fully established. Prune only for shape or to remove dead wood. Inspect for pests and disease annually.

4

Full Maturity

15+ years onward

Fully established tree providing year-round screening and landscape structure. Foliage maintains vibrant color through seasons.

Minimal care required. Water during extended drought periods. Prune only to maintain desired form or remove damaged branches. Monitor for bagworms and spider mites in warm climates.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black walnut (produces juglone toxin) Dense competing evergreens that shade the base Plants requiring dry conditions in areas of poor drainage

Common Pests

  • Hand-pick bags in fall/winter, or treat with Bacillus thuringiensis (Bt) in early summer when caterpillars are young

  • Increase humidity with regular misting; spray with neem oil or horticultural oil in spring and fall; use miticides if infestation is severe

  • Prune and remove infested foliage; apply neem oil or horticultural oil in spring

  • Apply horticultural oil spray in dormant season; use systemic insecticides if severely infested

  • Install tree guards or fence; use deer repellent sprays; plant in areas less accessible to deer

Uses

🏠

Screening and Windbreaks

Household

The narrow columnar form and dense foliage make 'Emerald Green' ideal for creating privacy screens and reducing wind exposure. Excellent for tight spaces where wide trees won't fit. [source]

🎨

Fresh Greenery for Arrangements

Craft

The aromatic, feathery foliage is prized by florists and crafters for wreaths, garlands, holiday arrangements, and fresh greenery bouquets. Branches have a pleasant, cedar-like scent. [source]

🦋

Wildlife Shelter and Food

Wildlife

Dense evergreen foliage provides year-round shelter, nesting sites, and food sources for songbirds, deer, and small mammals. Important for habitat corridors in landscaping. [source]

🏠

Ornamental Landscape Design

Household

The vibrant emerald-green color, columnar form, and low-maintenance nature make it a cornerstone plant for formal gardens, modern landscapes, and hedgerow designs. Provides vertical interest. [source]

💊

Aromatic and Respiratory Support

Medicinal

Western red cedar foliage contains volatile oils traditionally used in steam inhalations and teas for respiratory support. Modern research examines anti-inflammatory and antimicrobial properties. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

This is an ornamental tree, not harvested for food. Prune branches for fresh greenery arrangements or wreaths in late fall or winter. Remove dead or diseased branches as needed year-round. Light pruning to maintain form should be done in early spring before new growth.

Fun Facts

  • 🌱 The name 'Emerald Green' was given to this cultivar specifically because it maintains an unusually vibrant, bright green color even in harsh winters when many other evergreens turn bronze or yellow.
  • 🌱 Western red cedar is not a true cedar (genus Cedrus), but rather a species of arborvitae (Thuja). Native peoples of the Pacific Northwest traditionally used the bark for clothing, baskets, and canoes.
  • 🌱 'Emerald Green' is the narrow, columnar equivalent of the species and is often confused with 'Green Giant' (which is Thuja x 'Green Giant' and grows much larger and wider). The two are distinct cultivars with different growth habits.

Gardening Terms

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