How to Grow American Arborvitae Degroot's Spire

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American Arborvitae Degroot's Spire

Thuja occidentalis 'Degroot's Spire'

tree

Degroot's Spire is a narrow, columnar evergreen cultivar of Eastern Red Cedar prized for its tight, upright form and year-round foliage. It maintains a pencil-thin silhouette that makes it ideal for space-limited landscapes, screening, and formal hedges. The dense, feathery foliage is aromatic and transitions to warm bronze tones in winter.

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Example American Arborvitae Degroot's Spire timeline · Pittsburgh, PA (Zone 6b)

  1. Plant American Arborvitae Degroot's Spire

    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 Degroot's Spire

    Late summer into fall

    Before the first fall frost (≈ Nov 8)

Sample dates for Pittsburgh, PA. Sign up to get exact American Arborvitae Degroot's Spire dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6+ hours daily; tolerates partial shade but maintains tighter form in full sun
💧
Water: Moderate water needs; once established, very drought-tolerant. Water deeply at planting and during first growing season, then only during prolonged dry spells. Avoid waterlogging.
📏
Spacing: 24 inches
📅
Days to maturity: 3-5 years to reach ornamental maturity; continues growing for decades
🌱
Planting depth: Plant at same depth as root ball; top of root ball should be level with soil surface

Soil

Type: Well-draining loamy soil; adaptable to sandy, clay, and slightly alkaline soils
pH: 6.0-7.5
Amendments:
Peat moss or compost at planting for moisture retention Perlite or coarse sand if drainage is poor Slow-release balanced fertilizer at planting

Growing Zones

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Thrives in zones 2-8, highly cold-hardy and tolerant of northern climates

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

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Growth Stages

1

Establishment

4-8 weeks

Recently planted tree with developing root system; foliage appears slightly stressed or pale

Water regularly (2-3 times weekly) for first 4-6 weeks. Avoid fertilizing for first month. Mulch base with 2-3 inches organic material, keeping away from trunk.

2

Vegetative Growth

Spring through early summer (2-3 months)

Active shoot elongation; tree produces new feathery foliage and extends upward; color intensifies

Reduce watering frequency as roots establish. Apply balanced fertilizer (10-10-10) in spring. Remove any crossing branches. Prune only to maintain shape if needed.

3

Summer Maintenance

June through August (3 months)

Tree continues vertical growth; foliage is full and dense with vibrant green color

Water during dry periods (deep, infrequent watering preferred). Monitor for spider mites in hot climates. Mulch to retain moisture and regulate soil temperature.

4

Fall Hardening

September through November (3 months)

Growth slows; foliage may transition to bronze, copper, or warm brown tones in winter

Avoid late-season fertilizing which promotes tender new growth. Reduce watering. Apply anti-desiccant spray in late fall in cold climates to prevent winter damage.

5

Winter Dormancy

December through February (3 months)

Tree enters dormant state; maintains structural form and bronze winter color; minimal growth

No watering needed. Apply burlap wrapping only if exposed to heavy snow or ice damage risk. Inspect for winter damage or animal browsing.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Black Walnut (allelopathic toxins) Other tall conifers competing for vertical space Root-competitive trees and shrubs that crowd growing space Areas with poor air circulation prone to fungal disease

Common Pests

  • Spray with water to dislodge; use miticide if severe. Increase humidity. More common in hot, dry climates.

  • Hand-pick and destroy bags in fall/winter. Spray with Bt (Bacillus thuringiensis) in early summer when larvae are young.

  • Spray with insecticidal soap or neem oil in early spring. Most damage is cosmetic; rarely requires treatment.

  • Prune and destroy infested branch tips. Spray with spinosad or permethrin in early spring.

  • Install 6-8 foot deer fencing or apply deer-repellent sprays, especially in winter when food is scarce.

Uses

🏠

Winter Wreath & Fresh Arrangements

Household

The aromatic, fine-textured branches are highly valued for winter wreaths, garlands, and fresh flower arrangements. The bronze winter color adds visual interest to holiday displays. [source]

🏠

Privacy Screening & Living Windbreak

Household

The columnar form makes it ideal for creating tall, narrow visual barriers and windbreaks in limited spaces. Multiple plants can be planted in a line for living fences without consuming much horizontal space. [source]

🦋

Wildlife Shelter & Food

Wildlife

The dense foliage provides excellent nesting sites and shelter for birds and small wildlife. The tree offers protection from predators and harsh weather. [source]

💊

Traditional Herbal Uses

Medicinal

Thuja has been used in traditional herbalism and homeopathy for respiratory support, though modern medicinal use is limited. Essential oils contain thujone, a compound with antimicrobial properties. [source]

🎨

Essential Oil & Fragrance

Craft

The foliage contains aromatic volatile oils with a fresh, piney scent. These oils have been historically distilled and used in fragrances, though extraction is not common for home gardeners. [source]

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

Harvest Tips

American Arborvitae is not harvested for fruit or edible parts. However, branches can be cut for fresh arrangements or wreaths in fall/winter. Trim selectively to maintain narrow form; avoid heavy pruning which may not fill in. Minimal pruning maintains best columnar silhouette.

Fun Facts

  • 🌱 Degroot's Spire is named after a Dutch nurseryman and is sometimes called 'Green Emerald' or 'Emerald Green' in commerce, though these may be different (but very similar) cultivars.
  • 🌱 American Arborvitae is not actually a true cedar despite sometimes being called 'Eastern Red Cedar'—it's a member of the Cupressaceae (cypress) family, while true cedars are in the Pinaceae family.
  • 🌱 The foliage contains aromatic compounds including thujone, which gives it a distinctive fresh, piney fragrance that intensifies when brushed or crushed, naturally repelling some insect pests.

Gardening Terms

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