When the Haggerston Castle trees were rediscovered it was found that they too were hybrids of the same cross as those found by Naylor. The hybrid was given the name x Cupressocyparis leylandii.
The origin and outstanding growth rate of these hybrids soon aroused attention; and though they were to all intent sterile, it was found that they could be rooted from stem cuttings. As its qualities became better known, the tree was introduced not only to all parts of England, but into many foreign countries, including the United States.
In 1941, the first introduction of Leyland cypress to the United States was made with rooted cuttings at the Institute of Forest Genetics at Placerville, California. About 1950, the tree was introduced at the Strybing Arboretum in San Francisco and the University of Washington Arboretum in Seattle.
The first recorded introduction in the eastern United States was made at the U. S. National Arboretum in 1953. The introduction to the southern U. S. was made in
South Carolina in 1965 (
On good sites in the southeastern U. S., Leyland cypress may grow from 1-4 feet per year for 12 or more years. Level of soil fertility and the availability of water on well-drained sites determine rate of growth. The fastest growth is in full sunlight.
For an in depth treatise of Leyland cypress in the South, see the book The Leyland Cypress: A Tree of Beauty.1
1This information was excerpted from: Schoenike, R.E., and M.T. Gaffney. 1999. The Leyland Cypress: A Tree of Beauty. South Carolina Forestry Commission, Columbia, S.C. This book was published posthumously and
dedicated to the memory of Dr. Schoenike.
Dr. Ansel Miller, Professor Emeritus
Dr. Gene W. Wood, Professor and Extension Trails Specialist