How to Grow Green Giant Arborvitae

The Green Giant arborvitae is an especially fast-growing hybrid between the Western redcedar and Japanese arborvitae. Unlike some other evergreens, its rich, dense, green foliage does not yellow or brown in winter and only slightly bronzes or darkens. Mature trees reach up to 40 to 60 feet tall, growing densely, narrowly, and in a pyramidal habit. Leaves are small, glossy, and scale-like, emitting a wonderful fragrance when touched. The bark is dark brown and shaggy.

Grown as an ideal substitute for Leland cypress in the southeastern United States, this large, needled tree is easy to grow and generally free of pests and diseases.

Common Name	Green Giant arborvitae
Botanical Name	Thuja standishii x plicata ‘Green Giant’
Family	Cupressaceae
Plant Type	Tree
Mature Size	40-60 ft. tall, 12-18 ft. wide
Sun Exposure	Full, partial
Soil Type	Clay, loam, well-drained
Soil pH	Acidic, neutral, alkaline
Hardiness Zones	5-8 (USDA)
Native Area	Hybrid, no native range

Green Giant Arborvitae Care

Plant your Green Giant in suitable conditions with full sun and well-draining soil. During the first year or so after planting, it requires regular watering but once it's established, it is drought-tolerant and low-maintenance, requiring little to no pruning and no fertilization. Green Giant has few pest and diseases issues and is not often damaged by deer.

Planting Tips

• Plant the tree to define property lines, block noise, or a tough wind barrier.
• For a privacy hedge or security screen, plant trees 5 to 6 feet apart.
• For other uses, plant the trees further apart in small groups or as specimens.
• Establish groups of trees in lawns or in the background of landscapes.

Light

Green Giant arborvitae prefers full sun. It will tolerate part shade and in climates with hot summer thrives in some light afternoon shade.

Soil

Able to grow in a range of soils, including poor soil and clay, Green Giant does best in moist, fertile, well-drained loamy soil. Avoid wet soil that does not drain well and exposure to salt spray or salty soil.

Water

For the first couple of months after planting, the tree needs frequent watering to keep the soil evenly moist at all times. In the next stage and until the tree is fully established, which takes at least one year, it needs about one inch of water every week to ten days. Large established trees are very drought tolerant.

Apply a mulch layer 3 to 6 inches deep around the base of the tree to preserve soil moisture but keep it away from the trunk.

Temperature and Humidity

Green Giant tolerates temperatures down to -20°F and some snow and ice but it is not as winter-hardy as Emerald Green arborvitae, which is a better choice for a northern climate.

Fertilizer

Do not fertilize the tree at planting time or in the first year after planting. For the first few years, apply a tree fertilizer formulated for evergreen trees and shrubs, such as 4-3-4, in the early spring to promote vigorous growth. Established trees do not need any fertilization.

Pruning Green Giant Arborvitae

Covered in dense, dark, evergreen foliage from the ground up, the Green Giant arborvitae needs little to no pruning or shearing. Growing elegantly and consistently, it only needs to be pruned after suffering snow damage or for aesthetic reasons.

Propagating Arborvitae

A common method to propagate arborvitae is to take stem cuttings between July and March. Commercial growers expose the cuttings to intermittent mist to root, which is not practical for home gardeners.

Common Pests & Plant Diseases

Fortunately, Green Giant is more resistant to deer than most arborvitae. It has no major insect or disease issues. Keep an eye out for scale insects and bagworms, as well as root rot in poorly drained soils.

From: thespruce