The Leyland cypress, ''Cupressus'' × ''leylandii'', often referred to simply as leylandii, is a fast-growing
coniferous evergreen tree much used in
horticulture
Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and no ...
, primarily for hedges and screens. Even on sites of relatively poor culture, plants have been known to grow to heights of in 16 years. Their rapid, thick growth means they are sometimes used to achieve privacy, but such use can result in disputes with neighbours whose own property becomes overshadowed. The tree is a
hybrid
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
of Monterey cypress (''
Cupressus macrocarpa'') and Nootka cypress (''
Cupressus nootkatensis''). It is almost always sterile, and is propagated mainly by
cuttings.
History
![Cupressocyparis leylandii](https://upload.wikimedia.org/wikipedia/commons/1/1d/Cupressocyparis_leylandii.jpg)
In 1845, the
Leighton Hall, Powys
Leighton Hall is an estate located to the east of Welshpool in the historic county of Montgomeryshire, now Powys, in Wales. Leighton Hall is a listed grade I property. It is located on the opposite side of the valley of the river Severn to Powis ...
estate was purchased by the Liverpool banker Christopher Leyland. In 1847, he gave it to his nephew John Naylor (1813–1889).
Naylor commissioned
Edward Kemp to lay out the gardens, which included redwoods, monkey puzzle trees and two North American species of conifers in close proximity to each other –
Monterey cypress
''Hesperocyparis macrocarpa'' is a coniferous tree. It is commonly known as the Monterey cypress and is one of several species of cypress trees endemic to California.
The Monterey cypress is found naturally only on the Central Coast of Califor ...
and
Nootka cypress
''Callitropsis nootkatensis'', formerly known as ''Cupressus nootkatensis'' ( syn. ''Xanthocyparis nootkatensis'') is a species of trees in the cypress family native to the coastal regions of northwestern North America. This species goes by many ...
. The two parent species would not likely cross in the wild, as their natural ranges are more than apart, but in 1888, the hybrid cross occurred when the female flowers or cones of Nootka cypress were fertilised by pollen from Monterey cypress.
John Naylor's eldest son Christopher John (1849–1926) inherited Leighton Hall from his father in 1889. Christopher was a sea captain by trade. In 1891, he inherited the Leyland Entailed Estates established under the will of his great-great-uncle, which passed to him following the death of his uncle Thomas Leyland. On receiving the inheritance, Christopher changed his surname to Leyland, and moved to
Haggerston Castle
Haggerston Castle was a castle located in the county of Northumberland,England at Haggerston about south of Berwick-upon-Tweed. Only the tower, rotunda and stable block (Grade II listed buildings) remain. Today it is part of a caravan park ow ...
,
Northumberland
Northumberland () is a county in Northern England, one of two counties in England which border with Scotland. Notable landmarks in the county include Alnwick Castle, Bamburgh Castle, Hadrian's Wall and Hexham Abbey.
It is bordered by land ...
. He further developed the hybrid at his new home, and hence named the first clone variant 'Haggerston Grey'. His younger brother John (1856–1906) resultantly inherited Leighton Hall, and when in 1911 the reverse hybrid of the cones of the Monterey cypress were fertilised with pollen from the Nootka, that hybrid was baptised 'Leighton Green.'
The hybrid has since arisen on nearly 20 separate occasions, always by open pollination, showing the two species are readily compatible and closely related. As a hybrid, although fertility of certain Leyland cypress forms were recently reported, most Leyland cypress were thought to be sterile, and nearly all the trees now seen have resulted from cuttings originating from those few plants.
Over 40 forms of Leyland cypress are known,
and as well as 'Haggerston Grey' and 'Leighton Green', other well-known forms include 'Stapehill', which was discovered in 1940 in a garden in Ferndown, Dorset by M. Barthelemy and 'Castlewellan', which originated from a single mutant tree in the
Castlewellan estate arboretum in Northern Ireland. This form, widely propagated from the 1970s, was selected by the park director, John Keown, and was named ''Cupressus macrocarpa'' 'Keownii', 1963.
Description
A large, evergreen tree, ''Cupressus'' × ''leylandii'' reaches a size between 20 and 25 m high, with its leaves giving it a compact, thick and regular habit. It grows very fast with yearly increases of 1 m. The leaves, about 1 mm long and close to the
twig
A twig is a thin, often short, branch of a tree or bush.
The buds on the twig are an important diagnostic characteristic, as are the abscission scars where the leaves have fallen away. The color, texture, and patterning of the twig bark ar ...
, are presented in flaky, slightly aromatic branches. They are dark green, somewhat paler on the underside, but can have different colors, depending on the cultivar. The
crown
A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...
of many forms is broadly columnar with slightly overhanging branch tips. The branches are slightly flattened and densely populated with scaly needles. The tree bark is dark red or brown and has deep grooves.
The
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s are found in
cone
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
A cone is formed by a set of line segments, half-lines, or lines con ...
s about 2 cm in length, with eight scales and five seeds with tiny resinous
vesicle
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry)
In cell biology, a vesicle is a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form nat ...
s. With the tree being a hybrid, its seeds are
sterile. Over time, the cones shrink dry and turn gray or chocolate brown and then have a diameter of 1 cm.
Taxonomic status
''Cupressus'' × ''leylandii'' is a hybrid of two other cypress species: Monterey cypress (''Cupressus macrocarpa'') and Nootka cypress (''Cupressus nootkatensis''). The taxonomic status of Nootka cypress has changed over time, and this has affected the taxonomic status of the hybrid. Nootka cypress was first regarded as belonging in the genus ''
Cupressus'', but was later placed in ''
Chamaecyparis''. It has become clear, however, that when the genus ''Cupressus'' is defined to include ''Chamaecyparis'', it is
paraphyletic unless it also includes ''
Juniperus
Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...
''.
[ In 2004, Little et al. transferred the Nootka cypress to ''Callitropsis''.] Little (2006) proposed another alternative by transferring all the North American species of ''Cupressus'', including the Monterey cypress (''C. macrocarpa''), to ''Callitropsis''.
In some of these classifications, this and other hybrids of Nootka cypress become very unusual in being intergeneric hybrids, the only ones ever reported among the gymnosperm
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν ...
s. In 2010, Mao et al. performed a more detailed molecular analysis and redefined ''Cupressus'' to exclude ''Chamaecyparis'', but to include the Nootka cypress. It may be added that attempts to cross Nootka cypress with other ''Chamaecyparis'' species have been universally unsuccessful. The scientific name of Leyland cypress depends on the treatment of Nootka cypress. Where Nootka cypress is considered as ''Cupressus nootkatensis'', the hybrid is within the ''Cupressus'' genus and is therefore ''Cupressus'' × ''leylandii''. If both Monterey and Nootka cypress are considered as species of ''Callitropsis'', the hybrid is ''Callitropsis'' × ''leylandii''. However where the parents are treated as being in different genera, Leyland cypress becomes an intergeneric hybrid: if Nootka cypress is within ''Chamaecyparis'', the name of the hybrid becomes ×''Cupressocyparis leylandii'', and where it is treated as ''Xanthocyparis'', the hybrid becomes ×''Cuprocyparis leylandii''.
Two other similar hybrids have also been raised, both involving Nootka cypress with other ''Cupressus'' species:
:''Cupressus arizonica
''Cupressus arizonica'', the Arizona cypress, is a North American species of tree in the cypress family Cupressaceae, native to the southwestern United States and Mexico. Populations may be scattered rather than in large, dense stands.
Descripti ...
'' var. ''glabra'' × ''Cupressus nootkatensis'' (''Cupressus'' × ''notabilis'')
:''Cupressus lusitanica
''Cupressus lusitanica'', the Mexican cedar or cedar-of-Goa, is a species of cypress native to Mexico and Central America (Guatemala, El Salvador and Honduras). It has also been introduced to Belize, Costa Rica and Nicaragua, growing at altitu ...
'' × ''Cupressus nootkatensis'' (''Cupressus'' × ''ovensii'')
Adaptation
Leyland cypress is light-demanding, but is tolerant of high levels of pollution and salt spray. A hardy, fast-growing natural hybrid, it thrives on a variety of soils, and sites are commonly planted in gardens to provide a quick boundary or shelter hedge
A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoin ...
, because of their rapid growth. Although widely used for screening, it has not been planted much for forestry purposes. In both forms of the hybrid, Leyland cypress combines the hardiness of the Nootka or Alaska cypress with the fast growth of the Monterey cypress.
The tallest Leyland cypress documented is about tall and still growing. However, because their roots are relatively shallow, a large leylandii tends to topple over. The shallow root structure also means that it is poorly adapted to areas with hot summers, such as the southern half of the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
. In these areas, it is prone to develop cypress canker
Cypress canker is a disease affecting ''Cupressus'' species, caused by one of several species of fungus in the genus ''Seiridium''. Infection causes die-back of twigs and branches in susceptible cypress trees, with rapidly increasing amounts of d ...
disease, which is caused by the fungus
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...
''Seiridium cardinale
''Seiridium cardinale'' is a species of fungus. It is the primary cause of Cypress canker
Cypress canker is a disease affecting ''Cupressus'' species, caused by one of several species of fungus in the genus ''Seiridium''. Infection causes die ...
''. Canker causes extensive dieback and ultimately kills the tree. In California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
's Central Valley, they rarely live more than 10 years before succumbing, and not much longer in southern states like Alabama
(We dare defend our rights)
, anthem = "Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery
, LargestCity = Huntsville
, LargestCounty = Baldwin County
, LargestMetro = Greater Birmingham
, area_total_km2 = 135,765 ...
. In these areas, the canker-resistant Arizona cypress
''Cupressus arizonica'', the Arizona cypress, is a North American species of tree in the cypress family Cupressaceae, native to the southwestern United States and Mexico. Populations may be scattered rather than in large, dense stands.
Descripti ...
is much more successful. In northern areas where heavy snows occur, this plant is also susceptible to broken branches and uprooting in wet, heavy snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
. The tree has also been introduced in Kenya on parts of Mount Kenya.
The sap can cause skin irritation in susceptible individuals.
Commercialization
In 1925, a firm of commercial nurserymen
A nursery is a place where plants are propagated and grown to a desired size. Mostly the plants concerned are for gardening, forestry or conservation biology, rather than agriculture. They include retail nurseries, which sell to the general ...
specialising in conifers were looking for a breed that was fast-growing, and could be deployed in barren, windy and salty areas such as Cornwall. Eventually they found the six original trees developed by Leyland, and began propagating the species. In 1953, a freak tornado blew down one of the original trees at Haggerston (the other original five trees still survive), on which the research division of the Forestry Commission
The Forestry Commission is a non-ministerial government department responsible for the management of publicly owned forests and the regulation of both public and private forestry in England.
The Forestry Commission was previously also respon ...
started developing additional hybrids. Commercial nurseries spotted the plant's potential, and for many years, it was the biggest-selling item in every garden centre in Great Britain, making up to 10% of their total sales.
Uses
They continue to be popular for cultivation in parks and gardens. Leyland cypress trees are commonly planted to quickly form fence or protection hedges. However, their rapid growth (up to 1 m per year), their thick shade and their large potential size (often more than 20 m high in garden conditions, and they can reach at least 35 m) make them problematic.
Cultivars
The cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
'Gold Rider' has gained the Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...
's Award of Garden Merit (confirmed 2017), though the original hybrid has now lost its AGM status.
Other cultivars include 'Douglas Gold', 'Leighton Green', 'Drabb', 'Haggerston Grey', 'Emerald Isle', 'Ferndown', 'Golconda', 'Golden Sun', 'Gold Rider', 'Grecar', 'Green Spire', 'Grelive', Haggerston 3, Haggerston 4, Haggerston 5, Haggerston 6, 'Harlequin', 'Herculea', 'Hyde Hall', 'Irish Mint', 'Jubilee', 'Medownia', 'Michellii', 'Moncal', 'Naylor's Blue', 'New Ornament', 'Olive's Green', 'Robinson's Gold', 'Rostrevor', 'Silver Dust', 'Variegata', 'Ventose', and 'Winter Sun'.["Cupressocyparis leylandii"]
zipcodezoo Accessed 9 March 2009
Legal aspects
The plant's rapid growth and great potential height can become a serious problem. In 2005 in the United Kingdom, an estimated 17,000 people were at loggerheads over high hedges, which led to violence and in at least one case murder, when in 2001, retired Environment Agency officer Llandis Burdon, 57, was shot dead after an alleged dispute over a ''leylandii'' hedge in Talybont-on-Usk
Talybont-on-Usk ( cy, Tal-y-bont ar Wysg) is a village and community in Powys, Wales, in the historic county of Brecknockshire. It lies on both the Caerfanell river and the Monmouthshire and Brecon Canal, about from the River Usk. In 2001 ...
, Powys
Powys (; ) is a county and preserved county in Wales. It is named after the Kingdom of Powys which was a Welsh successor state, petty kingdom and principality that emerged during the Middle Ages following the end of Roman rule in Britain.
Geog ...
.
Part VIII of the United Kingdom's Anti-Social Behaviour Act 2003
The Anti-Social Behaviour Act 2003 (c.38) is an Act of the Parliament of the United Kingdom which almost entirely applies only to England and Wales. The Act, championed by then Home Secretary, David Blunkett, was passed in 2003. As well as str ...
, introduced in 2005, gave a way for people in England and Wales affected by high hedges (usually, but not necessarily, of ''leylandii'') to ask their local authority to investigate complaints about the hedges, and gave the authorities in England and Wales power to have the hedges reduced in height. In May 2008, UK resident Christine Wright won a 24-year legal battle to have her neighbour's leylandii trees cut down for blocking sunlight to her garden.
Legislation with similar effect followed in Northern Ireland, Isle of Man and Scotland.
Notable specimens
At the U.S. Space & Rocket Center in Huntsville, Alabama
Huntsville is a city in Madison County, Limestone County, and Morgan County, Alabama, United States. It is the county seat of Madison County. Located in the Appalachian region of northern Alabama, Huntsville is the most populous city in ...
, twenty leyland cypresses line an elevated berm in their Rocket Park area.
Gallery
File:X Cupressocyparis leylandii1.jpg, Trunk
File:Cupressus leylandii0.jpg, A 35-m-tall tree
File:Raindrops on leyland cypress.jpg, Foliage closeup
File:Cupressocyparis leylandii 'Castlewellan Gold'.jpg, Potted specimen
File:Starr 070308-5493 Unknown cupressaceae.jpg, Cultivated leyland
File:X Cupressocyparis leylandii3.jpg, A small tree
File:Cupressocyparis leylandii 'Naylor's Blue' OB Wrocław.jpg, In a botanical garden in Wrocław
Wrocław (; german: Breslau, or . ; Silesian German: ''Brassel'') is a city in southwestern Poland and the largest city in the historical region of Silesia. It lies on the banks of the River Oder in the Silesian Lowlands of Central Europe, rou ...
File:Cupressocyparis leylandii 'Castlewellan Gold' gold leafs.jpg, 'Castlewellan Gold' golden leaves
References
External links
*
{{Taxonbar, from=Q1290970
Cupressus
Hybrid plants
Trees of Wales
Flora of the West Coast of the United States
Garden plants of North America
Drought-tolerant plants
Ornamental trees
Plants described in 1926
Flora without expected TNC conservation status