Thuja occidentalis ‘Smaragd’ (American Arborvitae)

Prized for its emerald green color, award-winning Thuja occidentalis ‘Smaragd’ or ‘Emerald Green’ (Emerald Green Arborvitae) is a versatile, easy-to-grow conifer, ideal for gardeners seeking a medium-sized evergreen for privacy, wind protection, or as a decorative element in the landscape. Its low maintenance and adaptability make it a popular choice for a variety of garden settings.

Emerald Green Arborvitae: An In-depth Look

Thuja occidentalis ‘Smaragd’, commonly known as Emerald Green Arborvitae, is a popular ornamental conifer noted for its striking appearance and versatility in landscape design. Emerald Green Arborvitae is prized for its bright emerald green foliage, which retains its vibrant color throughout the year. It has a narrow, pyramidal growth habit with dense, compact foliage, making it an attractive choice for both formal and informal gardens.

Native: Thuja occidentalis is native to North America. It is predominantly found in the northeastern United States and southeastern Canada. This species naturally occurs in wet forests, swamps, and along lake shores, thriving in cool, moist, well-drained environments.

Plant Type and Habit: It is an evergreen conifer with a naturally narrow and pyramidal form. This cultivar is slow-growing, about 12 inches per year (30 cm), and prized for its upright growth and compact branching.

Size: typically grows to about 12-14 feet in height (3.6 to 4.2 meters) and 3-4 feet in width (90-120 cm), making it a medium-sized Arborvitae ideal for hedges and screening.

Foliage: The foliage consists of lush, emerald green leaves that are scale-like and densely packed, contributing to the plant’s full appearance. It maintains its lovely color year-round and does not turn bronze in winter.

Bark: The bark is reddish-brown, relatively smooth, and becomes more textured with age.

Uses: Ideal for creating privacy screens, hedges, windbreaks, or as a specimen plant. Its narrow growth habit makes it suitable for small gardens or tight spaces. A highly popular plant for use in hedgerows and borders.

Award: Recipient of the prestigious Award of Garden Merit of the Royal Horticultural Society.

Hardiness: Hardy in USDA zones 2-7, it can withstand cold winters and a range of environmental conditions. Forming a majestic exclamation point in the landscape, it is reliable and cold weather resistant and represents a valuable, hardy alternative to cypress.

Wildlife: American arborvitae provides nesting sites for songbirds, as well as cover, especially in the winter, for deer, which both feed on the branches and use them for shelter from the cold.

Toxicity: Generally considered non-toxic to humans and animals.

Deer and Rabbit: May suffer some damage from deer and rabbits, especially in areas where these animals are prevalent.

Invasiveness: This cultivar is not considered invasive and typically stays within its planted boundaries.

Benefits: Offers year-round color and privacy, is easy to maintain, and its compact growth habit makes it suitable for a variety of landscaping needs.

American Arborvitae Growing Tips

Light: Thrives in full sun but can also grow well in partial shade. Full sun exposure leads to denser foliage growth. Usually appreciates some light afternoon shade in hot summer climates. Protect from drying winds, especially when young.

Soil: Adaptable to a wide range of soils but prefers moist, well-drained, slightly acidic to neutral soil. Tolerates clay soils.

Water: Regular watering is important, especially for young plants and in dry conditions. Avoid extreme dry soil in the fall, which can cause the evergreen foliage to dry out in winter.

Fertilizer: Apply a balanced, slow-release fertilizer in early spring. Over-fertilization can harm the plant, so follow the recommended rates.

Pruning: Little to no pruning is required. Prune for shaping or size control in late winter or early spring before new growth starts. Avoid heavy pruning.

Mulch: Provide a generous root zone mulch.

Propagation: Propagated through semi-hardwood cuttings in late summer.

Pests and Diseases: Watch for bagworms, spider mites, mealybugs, and scale insects. Leaf tips may suffer damage from leaf miners. Canker can sometimes pose a problem. Fungal diseases like root rot can occur in poorly drained soils. Good air circulation and proper planting depth help prevent these issues.