Thuja occidentalis 'Smaragd' is a cultivar of the Eastern White Cedar, also known as the American Arborvitae. It is a slow-growing evergreen conifer that can eventually reach a height of around 4-5 meters (12-15 feet) and a spread of around 1-1.5 meters (3-5 feet). Thuja occidentalis 'Smaragd' is known for its slender, pyramidal shape, which makes it an ideal choice for hedges, screens, and topiaries. Its foliage is a vibrant green color that maintains its color throughout the year. The leaves are scale-like and form flattened sprays, which give the plant a delicate and fine texture.