Which Is Better: Cypress or 'Green Giant' Arborvitae?

Written by April Sanders; Updated December 27, 2018

Homeowners and landscapers looking for a fast-growing, evergreen tree to be used as a hedge or privacy barrier often narrow their choice to two plants: The "Green Giant" arborvitae (Thuja standishii x plicata "Green Giant") or a cypress called the Leyland cypress (× Cuprocyparis leylandii). Because each plant has its own pros and cons, which is better depends on personal preference and where and how the tree will be used.

One Tree or Two

A tree's background doesn't necessarily make it better than another tree, but the differences can still be interesting. One difference between these two trees is that one is a cultivar of two species and the other is a cultivar of two genera. Several trees in at least three genera are called "cypress," including trees in the Taxodium, Cupressus and Chamaecyparis genera, but it is the Leyland cypress that is the most commonly grown in home landscapes. The Leyland cypress is a hybrid of two cypress trees from the Cupressus and Chamaecyparis genera. "Green Giant," on the other hand, is a cultivar of two species from one genus: Thuja plicata and Tjuja standishii.

Looks May Be Everything ...

It's the fast growth and evergreen foliage of both trees that attracts home gardeners to these plants. "Green Giant" grows to a maximum average height of about 60 feet, with a maximum width of about 14 feet. In optimum environments, the tree can grow up to 4 feet per year. The Leyland cypress is a bit larger -- it grows to a maximum height of about 70 feet, with a maximum average width of around 15 feet. It grows up to 3 feet per year during its early years, according to Missouri Botanical Garden, and in the wild it can reach heights of over 100 feet. "Green Giant" has true, very dense green foliage, whereas the Leyland's foliage is less dense and more of a grayish-green hue.

... But Consider the Climate

"Green Giant" tolerates cold better than the Leyland cypress, but the latter tolerates heat better than the former. "Green Giant" is hardy in U.S. Department of Agriculture plant hardiness zones 5 through 8, and the Leyland cypress is hardy in USDA zones 6 through 10. Once established, the Leyland cypress can tolerate drought. "Green Giant," on the other hand, does not like hot, dry conditions.

A Caring Environment

Besides the climate, you also need to consider the environment. If you live in a hot climate and the planting site is shaded in the afternoon, for example, then the best tree would be "Green Giant," because it grows best with some afternoon protection from the hot sun. On the other hand, the Leyland cypress grows best in full, hot sunlight. Both trees like rich, well-draining soil, but "Green Giant" prefers soil on the moist side, whereas the Leyland cypress will tolerate drier conditions.

Ponder the Pests

When the Leyland cypress first burst onto the scene, it quickly became extremely popular. Easy to shape and fast-growing, it was rarely bothered by insect pests or diseases. Over time, however, this changed, according to the Clemson Cooperative Extension, and now the tree is known to suffer from a wide variety of problems, including issues with diseases and insect pests. Because the trees are so large, it is almost impossible to treat a sick Leyland cypress. Today, "Green Giant" is promoted as a better alternative to the Leyland cypress primarily because it is far less likely to succumb to serious disease or insect pests.

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