An evergreen with scale-like leaves, arborvitae (Thuja) is a popular choice for hedges because of its tall, narrow growth habit. It can also be used as a focal point in a mixed border of shrubs and flowers and is frequently used in foundation plantings.
About This Plant
Eastern arborvitae (Thuja occidentalis), also called eastern white cedar, and its cultivars are among the most commonly planted. This native of eastern North America grows wild in moist woods. While the straight species can grow as tall as 40-60 feet, the more widely planted cultivars have more restrained growth habits and make better landscape plants. 'Nigra', also known as 'Dark American', is a popular selection that keeps its deep green color all winter long; it grows 10-20 feet tall and 4-6 feet wide at maturity. 'Smaragd', also called 'Emerald Green', is finer textured and slower growing, reaching 10-15 feet tall and 3-4 feet wide. Where space is limited, 'Holmstrup' is a good choice, growing about 10 feet tall and 3 feet wide. Not all cultivars are columnar. 'Woodwardii' makes a globe-shaped shrub 4-8 feet high and 5-10 feet wide. 'Little Giant' has a similar growth habit but gets only 2-4 feet tall and wide. 'Golden Globe', at 2-3 feet tall and wide, makes a great accent with its bright gold foliage. Most eastern arborvitae are hardy in zones 4-7.
The western native, giant arborvitae or western red cedar (Thuja plicata), is larger and faster growing than its eastern relation, but not as cold hardy, growing well in zones 5-7. One of the most common cultivars is 'Green Giant' which has a fast growth rate (up to 5 feet a year under good conditions) and is tolerant of drought. It reaches 30-50 feet tall and 12-20 feet wide.
Oriental arborvitae (Thuja orientalis, now more correctly Biota orientalis) is the least hardy, to zones 6-11, and is best adapted to the south and southwestern parts of the country. Growing 18-25 feet tall and 10-15 feet wide, it is useful for hedges and as a specimen. There are many cultivars available with varying growth habits.
Good for hedges and screens
Arborvitae grows best in full sun, but will tolerate light shade. Giant arborvitae is the most shade tolerant. All prefer fertile, moist, well-drained soil.