How to Grow Techny Green Arborvitae

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Techny Green Arborvitae

Thuja occidentalis 'Techny'

shrub

Techny Green Arborvitae is a dense, narrow, columnar evergreen shrub prized for its cold hardiness and vibrant green foliage year-round. It maintains an attractive pyramidal shape with minimal pruning and grows at a moderate pace. This cultivar is exceptionally winter-hardy and widely used as a windbreak, screen, or accent plant in northern climates.

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Example Techny Green Arborvitae timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Techny Green Arborvitae

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. Harvest Techny Green Arborvitae

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

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

Growing Conditions

☀️
Sun: Full sun to partial shade, 6+ hours of direct sunlight daily for best color and density
💧
Water: Moderate watering; keep soil consistently moist but not waterlogged. Water deeply at planting and during dry spells. Drought-tolerant once established, but performs better with regular moisture. Reduce watering in fall to harden off for winter.
📏
Spacing: 36-48 inches (3-4 feet) apart for screening or windbreaks; can be closer for dense hedges inches
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Days to maturity: Not applicable for shrubs; reaches mature height (15-20 feet) in 15-20 years
🌱
Planting depth: Plant at same depth as root ball; do not bury the trunk collar

Soil

Type: Well-draining loamy to slightly moist soil
pH: 6.0-7.5
Amendments:
Compost or aged bark mulch at planting Peat moss for moisture retention Perlite if drainage is poor

Growing Zones

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Thrives in zones 2-7, exceptional cold hardiness makes it ideal for northern regions

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

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Growth Stages

1

Establishment (Year 1)

3-6 months

Young plant is settling into the landscape with active root development. Foliage may appear slightly stressed after transplanting but recovers quickly.

Water deeply 2-3 times weekly, apply 2-3 inches of mulch around base (keep away from trunk), avoid fertilizing in first year, provide shelter from harsh winds if transplanted in fall

2

Vegetative Growth (Years 2-3)

2-3 years

Plant develops a full, dense branching structure. New terminal growth extends the height and fills out the columnar form. Foliage deepens to rich green.

Water during dry periods, light pruning to shape if needed, apply balanced slow-release fertilizer in spring, maintain 2-3 inch mulch layer, no major pruning required

3

Mature Growth (Years 4+)

Ongoing

Plant reaches full columnar form and maximum density. Exhibits characteristic narrow, pyramidal silhouette with fine, feathery foliage.

Water during extended drought, minimal pruning except to remove dead branches or maintain shape, annual light fertilization optional, monitor for pests and disease, allow winter snow to fall naturally without shaking branches excessively

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black walnut (produces juglone toxin) Areas with poor drainage or standing water Salt-laden areas (road spray) Extremely windy, exposed sites without shelter

Common Pests

  • Hand-pick egg cases in winter, apply insecticidal spray in late spring when caterpillars emerge, use Bacillus thuringiensis (Bt) for organic control

  • Spray with strong water stream to dislodge, use horticultural oil or neem oil in spring and fall, maintain adequate moisture to reduce stress

  • Prune out affected shoots, apply insecticidal spray in late spring, maintain plant health to reduce susceptibility

  • and (fungal)

    Ensure excellent drainage, avoid overwatering, prune dead branches, apply fungicide if cankers appear, consider removal if severely affected

  • Install physical barriers or deer fencing, apply commercial deer repellent sprays, plant in areas with natural protection

Uses

🏠

Winter Windbreak & Privacy Screen

Household

Its dense, narrow columnar form makes it ideal for creating windbreaks and living privacy screens in cold climates. A row of Techny cultivars provides year-round visual screening and reduces wind penetration. [source]

🦋

Wildlife Shelter & Nesting

Wildlife

Dense foliage provides excellent shelter and nesting habitat for birds and small mammals, particularly valuable in harsh northern winters. [source]

🎨

Ornamental Landscaping

Craft

Its attractive, consistent pyramidal shape and vibrant green foliage make it a premium choice for formal gardens, entrances, foundation planting, and specimen use without requiring intensive shaping or maintenance. [source]

🏠

Cold Hardiness & Reliability

Household

Bred specifically for extreme cold tolerance (zone 2), Techny Green is one of the most reliable arborvitae cultivars for northern gardeners, withstanding temperatures well below -40°F. [source]

💊

Traditional Uses of Arborvitae

Medicinal

While not commonly used in modern herbalism, arborvitae has a history in traditional medicine and contains thujone, though consumption is not recommended due to potential toxicity. [source]

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

Harvest Tips

Techny Green Arborvitae is an ornamental shrub, not harvested for food or material. Prune minimally for shape; remove any dead, diseased, or damaged branches in late winter before spring growth. Light shaping can be done in early summer to maintain columnar form.

Fun Facts

  • 🌱 Techny Green was specifically developed by the University of Minnesota and cultivated at the Cass Nursery to withstand the brutal winters of Minnesota and surrounding regions, earning its name 'Techny' from the original Techny (now Kishwaukee College) area.
  • 🌱 Arborvitae is also known as 'white cedar' despite not being a true cedar; the name comes from French meaning 'tree of life' and dates back to its use by Native Americans for medicinal remedies.
  • 🌱 This cultivar retains its bright green color throughout winter better than many other arborvitae varieties, which often take on bronze or brownish tones in cold weather.

Gardening Terms

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

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