Leyland cypress and the shifting spectrum of names Derrick Rooney1 The late Alan Mitchell, dendrologist picked off a Nootka cypress. The Despite the unusual appearance for the British Forestry Commission, seedlings were sent to Haggerston and vigorous growth of the seedlings called it a silvicultural event on Castle, in Northumberland, for they attracted scant interest until a par with the invention of the planting in 1892. The clone later 1926, when they were brought to spade. A British judge called it the named ‘Haggerston Grey’ is one of the attention of William Dallimore, biggest single cause of litigation those seedlings. curator of the British National Pinetum between neighbours in Britain. Many at Bedgebury, who described them In 1911 two similar seedlings were New Zealand farmers who need and arranged for the ‘Haggerston raised at Leighton Hall from seed shelter in difficult situations regard it Grey’ and ‘Leighton Green’ clones collected off a Monterey cypress. as the best thing since sliced bread. to be propagated. ‘Naylor’s Blue’, These were later named ‘Leighton which grew near ‘Leighton Green’ on “It” is the Leyland cypress, the Green’ (Fig. 1A–B) and ‘Naylor’s a hillside behind Leighton Hall, was archetypal Cinderella tree, which Blue’. propagated only after it was felled by arose as a hybrid in England in the a freak windstorm in 1954. A fourth 1880s, was not recognised as special The name “Leyland” commemorates clone, ‘Green Spire’, remains less well until the 1920s, and did not become the family who owned the known. widely known even in Britain until the Haggerston and Leighton estates when the original seedlings were 1960s. The hybrid was a centenarian raised and propagated. C. J. Naylor Dallimore recognised the seedlings by the time the mass-production was managing the Leighton part as that uncommon occurrence, an techniques developed in the 1980s of the estates when the first batch intergeneric cross. The parents were made it available at an affordable of seedlings was raised in the determined to be the Monterey and price for shelter belts in New Zealand. 1880s. In 1892, after inheriting Nootka cypresses. This meant that both the estates, which had been under the international rules then Within the last 20 years, thanks to entailed under the will of his great- in force, a new name, incorporating its vigorous growth and its tolerance great-uncle Thomas Leyland, he moved to Haggerston (taking the bits of both generic names, had of exposure and a wide range of soil hybrid cypresses with him) and to be erected. This was to lead to and climatic conditions, the Leyland changed his surname to Leyland. considerable disruption and confusion cypress has become probably the Subsequently, he sold his lifetime later. second most often planted tree interest in Leighton Hall to his (behind radiata pine) in New Zealand. brother John Naylor, who died in 1906. John Naylor’s son, Captain Some of the clones available have J. M. Naylor, took over Leighton Hall even been talked about as possible in 1909 and remained there until sources of high-quality plantation 1931. He was probably the Naylor of timber. ‘Naylor’s Blue’. Unfortunately, it has another, less desirable, claim to fame. In the last two decades its shifting spectrum of scientific names has caused more confusion for nurseries, farmers, and Fig. 2 Storm-battered macrocarpa growing foresters than any other tree. A on the shoreline, South Bay, Kaikoura. Photo: Derrick Rooney. Leyland cypresses have been in New Zealand only about 60 years, At that time, the Monterey cypress which makes their popularity and was known to taxonomists as rapid spread all the more remarkable, Cupressus macrocarpa. This species given that they can only be is a native to California and is propagated vegetatively. commonly called “macrocarpa” in New Zealand (Fig. 2). The Nootka The Leyland cypress originated in cypress, also popularly known in the 1883 according to some accounts and American Pacific North-west as yellow 1888 according to others, at Leighton B spruce or yellow cedar, was classified Hall, Welshpool, Wales, as a chance Fig. 1 ×Cuprocyparis ‘Leighton Green’. in the same false-cypress genus as seedling in a batch raised from cones A, shoot. B, foliage. Photos: Derrick Rooney. the better-known Lawson cypress, 1 PO Box 43, Hororata, Canterbury, New Zealand; [email protected] New Zealand Garden Journal, 2013, Vol. 16(1) 23 and was known as Chamaecyparis nootkatensis. Nootka cypress is native to the west coast of North America, from Alaska to northernmost California. Dallimore coined the compound generic name ×Cupressocyparis and the specific name leylandii for the Leyland hybrids (Jackson and Dallimore, 1926). The name ×Cupressocyparis was subsequently used for all crosses between the Nootka and other American cypress species. Another two leylandii clones were selected in 1940 from a different source: seedlings from a macrocarpa growing at the small East Dorset town of Ferndown. The seed was raised at Fig. 3 ×Cuprocyparis ‘Silver Dust’, a variegated sport of ‘Leighton Green’. Photo: Derrick Rooney. the Barthelemy nursery at a nearby village, Stapehill, and although no A more recently named Leyland The “original” Leyland clones thrive Nootka cypress was known to be clone, ‘Silver Dust’ (Fig. 3), was almost anywhere in New Zealand growing in the vicinity two unusual raised in the United States from a below the treeline. In the United seedlings were determined to be of the branch sport on ‘Leighton Green’. Its States they are rated for USDA same parentage as Leyland cypress. green foliage is speckled with creamy Hardiness Zone 5 (hardy to -23°C, For many years these seedlings were white variegation at the tips. ‘Silver perhaps lower). known only under the Stapehill code Dust’ is available in New Zealand ‘Leighton Green’ was the first clone numbers, 20 and 21. but it’s not to everyone’s taste. It established in New Zealand. Although can be eye-catching as a specimen In 1956 the research division of it was grown commercially in Britain tree in the right context of other dark the British Forestry Commission from the 1930s little is known evergreen trees but does not make an sent a genetics team to Leighton about early attempts to import it to attractive hedge. Park to collect seed in the hope New Zealand. The first known attempt that new Leyland hybrids could A slower-growing, bright yellow clone, at acclimatisation was made in 1949 be raised from the original source. ‘Robinson’s Gold’, was released in by the North Otago Tree Planting They were unsuccessful in this, the mid-1970s. This was a chance Association, but the plants failed to but seed collected from an Arizona seedling, found in a rhododendron survive. The association’s minutes, cypress, then known as Cupressus garden near Belfast, Northern held in the North Otago Museum, glabra, growing about 20 metres Ireland. The older ‘Castlewellan Gold’ contain no record of a second attempt from the Nootka cypress that had originated after severe snowstorms in by them. An importation in 1952 by produced the original Leyland clones, the 1962–63 winter snapped a branch the then Department of Agriculture yielded two seedlings that displayed from a golden macrocarpa growing was successful, and the cultivar was unusual adult foliage. These were in the forest park at Castlewellan, in established at a research station at subsequently propagated and named County Down. A local nurseryman Rukuhia, near Hamilton, from where ×Cupressocyparis ‘Notabilis’. who sowed seed collected from the propagating material was presumably In 1961 a Mr Howard Ovens, from Tan- fallen branch selected a golden- distributed. coloured seedling that proved to be y-Cae, Dyfed, in Wales, collected seed Harry Hart obtained six plants, via a Leyland-type hybrid. ‘Castlewellan from a Mexican cypress, then known the then Forest Research Institute Gold’ was first marketed in Ireland as Cupressus lusitanica, near a grove (FRI) at Rotorua, for planting in in 1970 and has been available in of Nootka cypresses at the Westonbirt the H. E. Hart Arboretum at Lake New Zealand since the early 1980s. Arboretum in Gloucestershire. Two of Coleridge in 1961, but recorded in his Since 1980 numerous other clones the resultant seedlings were clearly notebook2 that the material supplied and sports of Leyland cypress crossed with Nootka cypress. One of had “weak root systems”. Three have been named in Great Britain, these, commonly known as ‘Ovensii’, plants died in his garden nursery. including some with coloured foliage. is grown in New Zealand and has The remaining three were planted Today, more than 40 Leyland cypress become popular, particularly in the as group No. 80 in the arboretum in cultivars have been named. Many North Island, where it seems to grow September, 1961, but two of them of these are almost certainly branch better than it does in the South Island died soon afterwards and the third sports. and produces timber of good quality. was removed in September, 1962. 2 Hart kept a bound notebook in which he recorded, from 1934 until shortly before he died in 1979, detailed observations of acquisition dates, sources, and planting dates of all the trees in the arboretum at Lake Coleridge. His notebook is currently held by the Central Canterbury Farm Forestry Association. 24 New Zealand Garden Journal, 2013, Vol. 16(1) Three replacement plants obtained only about 15 years old and the fact These seedlings, with their obvious from Lincoln University (then Lincoln that logs had been harvested from affinity to the Arizona cypress, were College) were planted as group some of them indicated rapid growth an interesting development, because No. 81 in September, 1962, at which because of the fertility of the site.