How to Grow American Arborvitae 'Emerald Green'

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American Arborvitae 'Emerald Green'

Thuja occidentalis 'Emerald Green'

tree

'Emerald Green' is a narrow, columnar evergreen conifer prized for screening, windbreaks, and ornamental hedging. It maintains a rich green color year-round and grows in a tight, upright form requiring minimal pruning. This cultivar is more cold-hardy and disease-resistant than many other arborvitae varieties.

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Example American Arborvitae 'Emerald Green' timeline · Pittsburgh, PA (Zone 6b)

  1. Plant American Arborvitae '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 American Arborvitae 'Emerald Green'

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact American Arborvitae 'Emerald Green' dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun to part shade; 6+ hours of direct sunlight daily for best color and density
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Water: Moderate moisture needs; keep soil consistently moist but not waterlogged, especially during establishment (first 2 years). Water deeply 1-2 times weekly in dry periods. Established trees are relatively drought-tolerant but perform best with regular watering.
📏
Spacing: 24-36 inches (2-3 feet) apart for hedges; 4-5 feet for specimen planting inches
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Days to maturity: Not applicable—this is a perennial tree that reaches mature size in 15-20 years
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Planting depth: Plant at same depth as root ball; do not bury the crown

Soil

Type: Well-draining loamy to clay loam soil
pH: 6.0-8.0
Amendments:
Compost at planting Peat moss for moisture retention Perlite or sand if drainage is poor

Growing Zones

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Thrives in zones 2-8, with best performance in zones 3-7

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

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Growth Stages

1

Establishment

1-2 years

Young transplants establishing root systems, developing new growth

Water regularly; mulch around base with 2-3 inches of organic mulch (keep away from trunk); protect from wind and harsh sun in first year

2

Early Growth

3-5 years

Active vertical growth, developing narrow columnar form, branching densifies

Continue consistent watering; apply balanced, slow-release fertilizer in spring; prune lightly to maintain shape if needed; avoid heavy pruning

3

Maturation

5-15 years

Tree reaches desired height (15-20 feet); foliage becomes dense and rich green; form is fully columnar

Reduce watering frequency but maintain consistent moisture; fertilize annually in early spring; remove any dead or diseased branches; light shearing for hedge maintenance

4

Full Maturity

15+ years

Established tree at full size and form; foliage fully dense with vibrant color year-round

Minimal maintenance; water during drought; monitor for pests and disease; selective pruning for shape; no fertilizer needed if soil is adequate

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black Walnut (allelopathic—toxic chemicals inhibit growth) Aspens (competitive roots) Water-saturated areas

Common Pests

  • Hand-pick bags in fall/winter; spray with Bt (Bacillus thuringiensis) in early summer; prune infested branches

  • Increase humidity with regular misting; spray with insecticidal soap or neem oil; strong water spray to dislodge mites

  • Remove and destroy infested foliage; spray with systemic insecticide in spring; prune for air circulation

  • Install 8-foot deer fence; apply deer repellent sprays; plant in groups (less attractive to deer)

  • and (fungal: Cytospora, Phytophthora)

    Ensure excellent drainage; avoid wounding branches; remove dead/diseased wood; improve air circulation; avoid overhead watering

Uses

🏠

Privacy Hedges & Windbreaks

Household

'Emerald Green' is one of the most popular choices for living privacy screens and windbreaks due to its narrow columnar form, dense foliage, and year-round coverage. A single row or double row creates an effective visual and wind barrier. [source]

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Ornamental Landscaping

Household

The striking rich green color and elegant columnar silhouette make 'Emerald Green' a premier ornamental focal point in formal and modern landscapes. It pairs well with contrasting textures and colors. [source]

🦋

Wildlife Shelter & Nesting

Wildlife

Dense branches provide excellent shelter, nesting sites, and food for birds and small mammals. The thick foliage offers protection from predators and harsh weather. [source]

🍳

Aromatics (Cedar/Incense Scent)

Culinary

Foliage emits a pleasant coniferous, slightly citrusy aroma often described as 'cedar' scent. Dried branches can be used in potpourri, sachets, and natural incense preparations. [source]

💊

Traditional Herbal Use

Medicinal

Historically, arborvitae foliage has been used in traditional herbal preparations, particularly by Native Americans, for respiratory support and immune function, though modern medicinal use is limited. [source]

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

Harvest Tips

Not harvested for produce; instead, prune selectively for shape and hedge maintenance. Light trimming in early summer encourages dense foliage. Avoid heavy pruning into brown wood, which doesn't regenerate well.

Fun Facts

  • 🌱 'Emerald Green' (also called 'Smaragd') was developed in Denmark and is the most popular arborvitae cultivar in North America, prized for being more cold-hardy and disease-resistant than the original 'Green Giant' variety.
  • 🌱 The name 'Thuja' comes from the Greek word 'thyia,' and arborvitae means 'tree of life'—a name given by French explorers when Native Americans used the tree to cure scurvy due to its high vitamin C content.
  • 🌱 'Emerald Green' can live 50-150+ years, making it an excellent long-term investment for landscape permanence and legacy planting.

Gardening Terms

New to gardening? Learn about terms used in this guide:

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