Arborvitae is one of the most versatile, easy-to-grow evergreens suited to cold northern landscapes, used as specimen plants, hedges, foundation plantings and windbreaks. Arborvitaes are highly adaptable plants. Not only can they be used in many ways, but another great asset is that arborvitaes grow quickly, making them a relatively affordable evergreen.Thuja is the botanical genus of arborvitae.
Unfortunately, it doesn't have an easy common name, although it is occasionally referred to as white cedar. Arborvitae is pronounced ar-bor-vi-te. There are many different species of arborvitae growing world-wide, but only members of the species Thuja occidentalis are truly hardy in our climate. Native to the northern and eastern sections of the Northern hemisphere, Thuja occidentalis is also called American arborvitae. There are several other species that are almost hardy for our area and, unfortunately, you often see them for sale by mass marketers in our area. We'd only recommend trying these other plants if you have a warm micro-climate and want to try a marginally hardy species. Arborvitaes are evergreens, but like many other evergreens, the color of their foliage may change during the cold weather. Several varieties develop a yellowish/brown overtone in winter. If this bothers you, try growing the 'Techny' variety. It is very resistant to winter discoloration. Arborvitae foliage looks like flat fans formed by small, overlapping scales. They are technically needles, but they don't look like it or feel like it. When you bruise the foliage of an arborvitae, it gives off a very pleasant fragrance, similar to perennial tansy, reminiscent of citrus. Adaptable, fast growing and easy-to-grow, what more could you ask for in a plant? Like all plants, arborvitaes do have their preferences. Ideally, they would like to grow in a sunny situation in rich, well-drained, neutral pH soil that stays evenly moist. Unlike many other plants that struggle when they don't get exactly what they want, arborvitaes adapt well to a wide variety of situations. They will tolerate heavy soil or moist soil. They also do well in a wide range of soil pH.
Arborvitaes will even do well in a shady situation (as long as it's not dark shade). Keep in mind that all plants need some special care until they have established a good root system. They develop their ability to withstand stress once they have settled in. When siting your arborvitae, there are a few special considerations. First, if you have deer, you may want to choose a different plant. Consider snow load: their branches are flexible and when arborvitaes are planted where the snow falls off the roof onto them, they can have problems with winter damage. Arborvitaes will also have occasional problems with an insect called red spider mite. This is most common on plants that are near a brick wall or planted under an overhang where they seldom get direct rain. Red spider mites love it hot, dry and dusty. Given those circumstances, they can do considerable damage to an otherwise healthy arborvitae. If you have to plant an arborvitae where those conditions exist, try to make a practice of rinsing the dust off the plant on a regular basis during warm weather. Red spider mites are sucking insects that are so small you can't see them on the foliage. They give a rough, sandy, speckled appearance to arborvitae foliage. If you suspect you might have spider mites, place a sample in a plastic bag and bring it in to a horticulturist at Bachman's for diagnosis and treatment recommendations.
One of the best features of arborvitaes is their tolerance of being sheared on a regular basis, making them good candidates for formal plantings and hedges. They should be pruned in early summer (right after the new growth has fully expanded) and they can be pruned again in mid- to late-August. The key to keeping pruned arborvitaes looking good for years and years is to start early and stay after them. If you want to keep them pruned to a four foot hedge, don't wait until they are five feet and try to hold them back. Starting before they reach the desired size encourages good thick growth and strong branching.
Like all evergreens, arborvitaes will shed some of their inner, oldest growth each year. Evergreens do not hold their needles forever, they just hold them year-round for several years. How long an evergreen holds its foliage depends on the variety. Arborvitae tend to hold foliage 3-4 years. As the plant ages, each fall the oldest foliage will yellow, brown and shed. That is natural. Arborvitae varieties can be grouped together as either globe form or upright form. Globe arborvitae basically grow the same height and width. Upright arborvitae vary greatly in height, but they are all significantly taller than they are wide. Here is a list of the varieties of arborvitaes that are commonly available in local nurseries. Unless otherwise noted, they are all hardy to Zone 3. We have noted those varieties that are more shade tolerant than others. If you are interested in a variety that isn't on this list, stop by and ask one of our horticulturists. They can probably find out more about it for you.
Varieties of Arborvitaes
Brandon Thuja occidentalis 'Brandon' Upright form; 12-15' tall x 6-8' wide; green foliage; narrow upright with finely textured foliage; resistant to winter burn
Degroot's Spire Thuja occidentalis 'Degroot's Spire' Upright form; 6' tall x 24" wide; green foliage; narrow, slow-growing variety that requires very little pruning
Gold Cargo Thuja occidentalis 'Gold Cargo' Upright form; 12-15' tall x 6' wide; greengold foliage; columnar evergreen; foliage tinged gold; tolerates light shade
Golden Thuja occidentalis aurea Globe form; 30" x 30"; golden-yellow foliage; broad growth habit that is sometimes conical; tolerates light shade
Hetz Midget Thuja occidentalis 'Hetz Midget' Globe form; 30" x 30"; dark green foliage; dense form that does well sheared; tolerates light shade
Holmstrup Thuja occidentalis 'Holmstrup' Upright form; 5-10' tall x 24" wide; bright green foliage; narrow habit; tolerates moist soil; tolerates light shade
Little Giant Thuja occidentalis 'Little Giant' Globe form; 30" x 30"; dark green foliage; dense form that does well sheared; slow growing variety; tolerates light shade
Pyramidal Thuja occidentalis 'Pyramidalis' Upright form; 12-25' tall x 3-6' wide; green foliage; narrow pyramid with soft-textured foliage; tolerates light shade
Rushmore Thuja occidentalis 'Rushmore' Upright form; 12-25' tall x 3-6' wide; dark green foliage; compact, narrow form; resistant to winter burn; good wind tolerance
Sherwood Moss Thuja occidentalis 'Sherwood Moss' Globe form; 48" x 48"; blue-green foliage; conical; attractive variety with foliage; foliage may bronze in winter
Sunkist Thuja occidentalis 'Sunkist' Upright form; 6-8' tall x 4-5' wide; golden-yellow foliage; dense; fast growing; tolerates light shade; only hardy to Zone 4
Techny Globe Thuja occidentalis Globe form; 3-5' x 3-5'; dark green foliage; resistant to winter burn; slower growing than some other varieties; tolerates light shade
Techny Thuja occidentalis 'Techny' Upright form; 12-15' tall x 6-8' wide; dark green foliage; broadly pyramidal form; dense foliage; holds color in winter