Prized for its emerald green color, award-winning Thuja occidentalis ‘Smaragd’ or ‘Emerald Green’ (American Arborvitae) is a semi-dwarf, evergreen shrub of compact, narrow, upright habit with erect sprays of glossy, bright green foliage. Slow growing, this American arborvitae can reach 12-14 ft.
I. Appearance and Characteristics
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.
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.
It 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.
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.
The bark is reddish-brown, relatively smooth, and becomes more textured with age.
Emerald green arborvitae is considered toxic to animals, though only mildly so, unless massive amounts are ingested. The issue lies in the plant’s essential oils, which contain the neurotoxin known as thujone, the largest concentration of which can be found in the cones, wood, and at the end of the twigs. If you notice your animal exhibiting any of the issues below, contact an emergency vet immediately.
II. How to Grow and Care
Sunlight
Emerald green arborvitae should be grown in full sun or partial shade. They generally need at least six hours of sun daily, but too much direct sunlight can stress the plant and burn the foliage. However, they should not be planted in full shade either, since this can greatly reduce the density of the foliage.
Temperature
Emerald green arborvitae does better in cooler, dryer climates. In very humid conditions, fungal diseases can be a problem. To help prevent this, plant your trees at least 3 to 4 feet apart from one another in order to improve air circulation. Avoid exposed, windy locations, especially in colder climates.
Watering
Your arborvitae will need watering twice weekly for the first few months after planting, then weekly watering (about one inch) for the next year or so. Once established, make sure it gets about a half-inch of water weekly, either through rainfall or irrigation. Too little water will cause the foliage to turn yellow or brown, while excessive water may cause needle discoloration and root rot.
Soil
Plant arborvitae in moist but well-drained soil that boasts a neutral to alkaline pH level. These shrubs do not like to have their roots in soggy soil, so apply a heavy layer of compost or mulch over the root zone each year to preserve soil moisture.
Fertilizing
Arborvitae plants normally do not need feeding. However, if new growth is very sparse or slow, an application of a balanced fertilizer containing all major nutrients is recommended.
Pruning
Light pruning in the early spring can help your arborvitae remain neat and foster thicker growth. To do so, trim the leafy parts of the branch, making sure not to cut back to bare wood. Dead or diseased branches should be removed to prevent decay and improve air circulation.
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.
III. Uses and Benefits
Thuja occidentalis ‘Smaragd’ offers several advantages over other types of hedges, making it a preferred choice for different garden environments. Its tolerance of full sun and partial shade makes it adaptable to a range of light conditions, allowing for flexibility in landscaping design. The compact growth habit and vibrant foliage of Thuja Smaragd make it
an excellent option for creating privacy screens, windbreaks, and formal hedges in both residential and commercial settings. Additionally, its low-maintenance nature and resistance to pests and diseases ensure reliable performance and long-term beauty in the landscape.