How to Grow Techny Blue Arborvitae

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Techny Blue Arborvitae

Thuja occidentalis 'Techny'

shrub

Techny Blue Arborvitae is a hardy, columnar evergreen shrub with soft, feathery blue-green foliage that turns bronze-purple in winter. This cultivar is prized for its compact, narrow form and exceptional cold tolerance, making it ideal for windbreaks, hedges, and ornamental landscapes in northern climates. It maintains its attractive color year-round and requires minimal pruning once established.

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

  1. Plant Techny Blue 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 Blue Arborvitae

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

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

Growing Conditions

☀️
Sun: Full sun to partial shade, 4-6 hours of direct sunlight daily
💧
Water: Moderate watering; keep soil consistently moist but not waterlogged, especially during establishment and hot, dry periods. Once established, it is quite drought-tolerant.
📏
Spacing: 24 inches
📅
Days to maturity:
🌱
Planting depth: Plant so root ball is level with or slightly above ground surface

Soil

Type: Well-draining loamy or sandy soil
pH: 6.0-7.5
Amendments:
Peat moss for moisture retention Perlite or coarse sand for drainage Compost for organic matter

Growing Zones

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Thrives in zones 2-7, with exceptional cold hardiness to -40°F

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

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Growth Stages

1

Transplant/Establishment

First year (12 months)

Young plant has been recently planted with visible root ball; foliage is bright blue-green and relatively compact.

Water deeply 2-3 times per week; mulch around base to retain moisture and regulate soil temperature; avoid fertilizing in the first year.

2

Active Growth

Years 2-3

Plant is vigorously establishing itself with upright branching and dense, columnar form developing; foliage remains blue-green.

Continue consistent watering during dry spells; apply light organic mulch layer; minimal pruning except to remove dead wood or shape lightly.

3

Mature Vegetative

Years 4+

Plant reaches its full upright columnar form (typically 15-20 feet tall and 3-4 feet wide); foliage is full and dense with blue-green summer color.

Water during extended drought periods; occasional pruning to maintain shape; monitor for spider mites and bagworms.

4

Winter Color Transition

October to March

As temperatures cool in fall, foliage transitions to bronzy-purple or russet tones, creating ornamental winter interest.

No special care needed; this is a natural and desirable color change; avoid heavy pruning in late fall as new tender growth may be damaged by frost.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black walnut (produces allelopathic compounds) Black locust Plants preferring acidic soil below pH 6.0

Common Pests

  • Spray with strong water stream to dislodge; apply miticide or neem oil if infestations are severe; increase humidity around plant.

  • Hand-pick bags in late fall or winter; apply Bt (Bacillus thuringiensis) in late spring when young caterpillars emerge; use pheromone traps.

  • Prune and destroy affected branch tips; apply systemic insecticide in early spring; maintain plant vigor with proper watering.

  • Prune out heavily infested branches; apply horticultural oil spray in dormant season; use insecticidal soap during growing season.

  • Ensure excellent drainage; avoid overwatering; remove infected plants if disease is severe; apply fungicide to surrounding soil.

Uses

🏠

Winter Greenery & Evergreen Arrangements

Household

Branches and foliage are attractive for fresh holiday arrangements and winter decorations. The blue-green color and feathery texture add visual interest to wreaths, garlands, and table arrangements. [source]

🦋

Wildlife Shelter & Nesting

Wildlife

Dense columnar form provides excellent shelter and nesting habitat for birds and small mammals. The evergreen branches offer year-round cover in harsh winter climates. [source]

🏠

Windbreak & Privacy Screen

Household

The narrow, upright form makes Techny Blue ideal for creating living windbreaks and privacy screens along property lines. It can withstand strong winds and exposure to salt spray. [source]

🎨

Ornamental Landscape Feature

Craft

The striking blue-green summer foliage and bronzy-purple winter color provide year-round ornamental interest. Its formal columnar shape works well in contemporary and traditional landscapes. [source]

💊

Traditional Herbal Use

Medicinal

Thuja species have a long history in traditional herbalism and homeopathy, though modern medicinal use is limited and should only be under professional guidance. Leaves contain thujone, a volatile compound. [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 Blue Arborvitae is not harvested for fruit or foliage in the traditional sense. However, branches can be cut for ornamental evergreen arrangements in winter. Foliage may be pruned lightly in spring (April-May) to maintain shape and remove winter-damaged growth. Avoid heavy pruning as the plant does not regenerate well from old wood.

Fun Facts

  • 🌱 Techny Blue was developed in the 1950s specifically for northern climates and is named after Techny, an unincorporated community in Illinois; it can survive temperatures as low as -40°F.
  • 🌱 The winter color transition to bronze-purple is a survival adaptation that helps protect the foliage from winter desiccation and UV damage in cold, sunny conditions.
  • 🌱 Eastern white cedar (a common name for Thuja occidentalis) was used by Native Americans and early colonists to make medicinal teas rich in vitamin C, earning it the historical name 'arbor vitae' meaning 'tree of life.'

Gardening Terms

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