It is widely chosen for hedge planting because it can produce an effective hedge in three to five years, because it will grow in virtually any soil and because it is indifferent to pollution and exposure, but few people, who buy it, understand that it will grow into an uncontrollable 'beanstalk'.

The nurserymen push it because they can grow it easily and therefore sell it cheaply, and in enormous numbers. More recently the Supermarkets, and other large retail outlets, have also realised how much profit is to be made out of the Leyland Cypress. Many of these do not scruple to stress those qualities which appeal to the city dweller's craving for privacy, but only a few of the more responsible of these organisations give equal weight to the fact that these same qualities make it a potential source of distress to neighbours.

Controlling the tree soon becomes an onerous annual chore. If the trimming of the sides is neglected, for a short while only, it may be necessary, because of the rapid growth, to cut back into the old wood. This will leave ugly dead sticks which will never produce leaves again. The dry heart of the tree is extremely flammable and if it catches fire will burn like a torch. If planted close to a house these hedges constitute a fire hazard. If allowed to grow naturally, the tree is apt to lose lower branches in heavy snow, and this can result in tall, but very scruffy looking hedges.

At first glance the Leyland Cypress seems a God-given answer to lack of privacy in crowded urban society: a second glance reveals the prospect of vast areas of suburbia under dense high forest of over 30 metres.

At Bedgebury Pinetum in South East England the Leyland Cypress were 130 ft (41.6 m) tall, at the time the Forestry Society Website was composed, and are still growing strongly. No one knows the height of a mature Leyland cypress as no mature tree yet exists.


Parentage

The tree is a hybrid between the Monterey Cypress (Cupressus macrocarpa) and the Nootka Cypress (Chamaecyparis Nootkatensis). These trees are not closely related and their offspring are possessed of hybrid vigour to a remarkable degree. It grows faster than either of its parents,and promises to grow much higher than either.

The Monterey Cypress grows wild on only a mile or so of low cliffs near Monterey in California. The Nootka Cypress, a very hardy tree, grows on the slopes just below glaciers and snow from Alaska to Oregon. The two trees do not normally meet in their wild habitat.


History

Six plants of the hybrid were first raised from the seed gathered from of a nootka in 1880. The parent tree is at Leighton Hall in Powys. They were sent in 1892 to Mr Leyland's estate in Haggerston Castle near Berwick, where all six still stand today among caravan holiday homes. This is the commonest form of the tree and has grey-green slender well-separated shoots. Another form arose, again in Leighton Hall, this time from seed gathered from a the Monterey Cypress. One of these still survives on the hill at Leighton Hall and in the early 1980s was 30 metres by 110 centimetres, (about 98 feet high). This form is called the 'Leighton Green'. It is a much brighter green. The finest shoots are closely set and broader and gives the tree a denser appearance than the 'Haggerston Grey'. This tree was the one first sold by Hilliers and so is the commonest in older gardens.

Two golden forms have since been raised in Ireland. One, the 'Castlewellan Gold' came from a cone from a branch broken off a golden monterey cypress by the 1963 snows. The male parent was a golden Nootka which stood beside the Monterey. Whereas the 'Castlewellan' has foliage like the 'Haggerston', the foliage of the other golden form, 'Robinson's Gold' more closely resembles that of the 'Leighton Green'. Alan Mitchell observes in one of his tree books that 'Castlewellan Gold' should 'diversify the impending urban forests' as it grows about as fast as the green forms and was being planted 'with abandon'.