Green Giant Arborvitae (Thuja standishii x plicata 'Green Giant')

Green Giant Arborvitae

Thuja standishii x plicata 'Green Giant'

A vigorous, fast-growing evergreen hybrid known for its rich green foliage and exceptional landscape screening. Coniferous tree.

Prefers full sun for the densest growth, but tolerates partial shade.
1/week
Easy
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Plant Needs

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Sunlight Prefers full sun for the densest growth, but tolerates partial shade.
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Watering Requires moderate watering during establishment; highly drought-tolerant once mature.
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Temperature Highly adaptable, thriving in USDA Zones 5 through 8.
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Characteristics

  • Leaves: Scale-like, tightly appressed, rich green foliage arranged in flattened sprays that darken slightly in winter but do not yellow;
  • Form: Pyramidal to conical habit with dense, uniform branching all the way to the ground;
  • Bark: Reddish-brown, fibrous, and exfoliating in narrow longitudinal strips on mature trunks;
  • Cones: Small, upright, oblong seed cones, approximately 1.2 cm long, emerging green and turning brown at maturity.
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Care Guide

Watering

Water deeply once a week during the first two growing seasons; established trees rely on natural rainfall.

Fertilization

Apply a balanced, slow-release evergreen fertilizer at the drip line just before new growth begins.. Fertilize lightly only during the first few years of establishment; mature trees rarely need supplemental feeding.

Coffee Grounds Compost:Mix used coffee grounds with standard garden compost and spread a thin layer around the drip line in early spring. This provides a gentle nitrogen boost and helps maintain slight soil acidity. Avoid piling directly against the trunk.
Pruning
  • Timing: Prune in early spring or mid-summer if shaping or height control is desired;
  • Method: Lightly shear the outer green foliage to maintain a tight hedge; never cut back into old, brown wood as it will not regrow;
  • Maintenance: Naturally maintains a uniform pyramidal shape, so pruning is strictly optional;
  • Clearance: Remove any dead, broken, or diseased branches as soon as they are noticed.
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Toxicity

Warning: this plant may be toxic.

Pets & Humans

Pets: Non-toxic per ASPCA; ingestion of large amounts of foliage may cause mild, self-limiting gastrointestinal upset.

Humans: Generally safe; prolonged skin contact with foliage or sap may cause mild dermatitis in highly sensitive individuals.

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Garden Uses & Culture

Culture: Celebrated in American landscaping as the ultimate fast-growing privacy screen, it has largely replaced the disease-prone Leyland Cypress in suburban and rural estates.

Usage: Extensively used for privacy hedges, windbreaks, noise reduction screens, and as a standalone specimen tree.