Leyland Cypress, Cupressocyparis leylandii

Summary

Foliage: Scale-like; evergreen

Height: About 80 feet

Spread: About 20 feet

Shape: Narrow conical

Main Features

Leyland cypress is a fast-growing conifer that is one of the most popular landscape conifers in the eastern U.S. In addition to its vigor, this species is relatively drought tolerant and can be pruned into a hedge. However, the widespread use has revealed an Achilles heel, proneness to disease. Disease problems (including Seridium, Botryosphaeria, and Phytophthora) are observed mostly, but not entirely, on stressed plants. Such a potential liability begs the question “should leyland cypress be used in our landscapes?” There is no clear-cut answer. One can travel throughout the eastern U.S. and observe that the great majority of leyland cypress trees and hedges are thriving. The best recommendation on the landscape use of this species is to minimize the amount of stress, i.e., do not plant leyland cypress in poor soils and irrigate during periods of drought. An alternative recommendation would be to use other similar conifers such as Thuja ‘Green Giant’ or Thuja Steeplechase®. There are a few cultivars that vary in plant form (more or less dense, columnar, and conical) and foliage color (greens, yellows, and blues). While leyland cypress is rated as a zone 6 species, plant damage/death occurred in zone 6a (Blacksburg, VA) following the all time record low winter temperature of -18o F on February 21, 1985.

Plant Needs

Zone: 6 to 10

Light: Full sun

Moisture: Average to somewhat dry

Soil type: Average

pH range: Acid

Functions

The tall narrow conical form of leyland cypress is useful as a privacy barrier or windbreak. This species can be pruned as a hedge, or occasionally be topped to control the height in which case it will re-grow a new top.

Care

As mentioned, plant leyland cypress in a non-droughty soil and irrigate during drought periods to minimize the occurrence of disease. Bagworms can be a potential serious problem. During the nursery production of leyland cypress, plants are often sheared to promote a dense full form. This practice often results in plants having multiple trunks which can split apart in heavy snow or ice storms.

Additional Information

The regularly used scientific name listed at the top of this article (×Cupressocyparis leylandii) will be changed in the near future (this publication is penned in early July 2011). The most appropriate name for leyland cypress is a matter of scientific debate. Scientists claim that ×Cuprocyparis leylandii or Calllitropsis ×leylandii is the correct name. Thus, leyland cypress may soon have a new scientific name (other than listed on the top of this page). Of course, this new name may be changed as well, so the name saga may continue for some time.