Family: Cupressaceae
Common Name: Cypress

This genus of around 20 species of conifers occurs in the warm temperate regions of the northern hemisphere, with the greatest number in the south-west of North America. Some species are found in the Himalayas, while C. sempervirens is a native of the Mediterranean and western Asia. Generally very isolated from one another geographic-ally, they are very close in character. The cypresses are striking trees, noted for their rapid growth and robust appearance under such adverse conditions as hot, dry climates, hard soil and exposure to strong wind. They come in a variety of shapes, colours and foliage textures. Unlike the closely related Chamaecyparis, they have provided few, if any, dwarf cultivars.

Species

C. cashmeriana, Kashmir cypress, zone 9, is one of the most beautiful of all the conifers. It is a pyramidal-shaped tree, to 30 m (100 ft), with lacy, pendulous, blue-gray foliage. This species can tolerate only very light frost and prefers a sheltered position.

C. glabra (Synonym: C. arizonica var. glabra), Arizona cypress, zone 7, is a dense, column-shaped tree, to about 15 m (50 ft), broadening with age. Its most outstanding characteristic is the blue-gray colour of the foliage. It has crowded, cord-like branchlets, which grow quite thickly, closely arranged leaves and reddish, flaking bark. This frost-hardy species does very well in dry regions, but can also tolerate coastal conditions.

C. funebris, Chinese weeping cypress or mourning cypress, zone 8, a native of China, is an attractive, trouble-free tree which generally grows to about 15 m (50 ft) tall, with a rather short trunk and a broadly pyramidal crown. The lower limbs spread close to the ground, the small branchlets arranged in pendulous sprays. The mature tree bears an abundance of small, brown cones.

C. lusitanica, Portuguese or Mexican cypress, zone 9, was introduced to Europe in the 16th century. Although quite variable, it can grow into a broad-headed tree up to 20 m (65 ft) tall, with gray-green foliage and slightly pendulous branch tips. The short, fine branchlets, sharp-tipped leaves and smallish, globular cones are characteristic of this attractive tree. It is a fairly fast grower and can tolerate warm conditions. Cultivar 'Glauca Pendula', a smaller tree of irregular, spreading habit, with large, weeping branches, is quite popular.

C. macrocarpa, Monterey cypress, zone 8, is almost extinct in its native habitat around Monterey on the Californian coast, but in cultivation is known for its vigor and size, up to 25 m (80 ft). It thrives as a windbreak or shelter plant in mild to warm regions, although it can be prone to insect attack and disease in some areas. The foliage is dull green and emits a characteristic smell when it is crushed, and the shiny brown cones also vary in length. Sometimes this tree forms a straight, central trunk, with a central leader; at other times it branches low into many large limbs, which ascend at an angle, their leading shoots eventually dominating the crown of the tree and giving it a characteristic, spiky outline. There are several golden-foliage cultivars of C. macrocarpa and these are more popular than the species. The best known is 'Goldcrest', which forms a narrow cone shape decked in dense, bright golden foliage. It grows to about 5 m (16 ft) in height and makes an eye-catching specimen plant in the garden. Other good golden cultivars include 'Donard Gold', with a tall, conical habit of growth; 'Golden Pillar' which also forms a narrow cone shape; 'Horizontalis Aurea', a small grower with a broad, flat habit; and 'Lutea' which forms a broad column up to 28 m (90 ft) in height, whose young foliage is yellow.

C. sempervirens, Italian cypress or pencil pine, zone 8, is an outstanding feature of Mediterranean landscapes, having grown there since ancient times. It reaches up to 30 m (100 ft) tall, even in cultivation, and can be distinguished by its very large, pale brown cones (which appear even on young trees), its dense, dark gray-green foliage, its fine branchlets arranged in small, flattened sprays, and its dense, small, blunt-tipped leaves. It has a columnar shape, the very slender column changing with maturity to a broader outline, while C. sempervirens 'Stricta' is a narrow, columnar form, with dense, dark green foliage. C. sempervirens has given rise to few cultivars however, though 'Swanes Gold' has become popular in home gardens. It forms a narrow, tapering, dense column of light yellow or green-yellow. Though it is smaller and slower growing than the species, it can reach to heights of 6-8 m (20-26 ft).

C. torulosa, Bhutan cypress, zone 8, originating from the Himalayas, is a variable species, especially in growth habit. It can be recognized by its bright green foliage, its long, thin, slightly curved branchlets, its crowded, overlapping scale leaves and its smallish cones, similar to those of C. lusitanica. The most highly valued form of this species is a densely foliaged tree, about l5 m (50 ft) tall, with a broadly based crown, often touching the ground, but narrowing higher up and tapering into a long, cone-shaped apex. Not as fast growing as some other cypresses, it is often seen in cool areas where it is long lived.

Cultivation

The cypresses are remarkably hardy and adaptable, so it is difficult to generalize about soil preferences. As with most conifers, they do not do well in very shallow, nutrient-deficient soils. The soil should be improved by the addition of organic matter and applied fertilizer. Most species prefer a climate with cold winters and hot summers, and a relatively dry atmosphere. They grow into very shapely trees when planted out in the open. Cypresses also thrive on exposure to wind (though for most species not salt-laden wind) and generally do not require staking if planted out when small. Pruning is not normally necessary, though cypresses can be clipped into topiary or arches. They can be easily propagated from seed; the seedlings grow extremely quickly and should be planted out when young. They will also grow from cuttings, this method being necessary for named cultivars or where a particular growth form is required. They do not strike easily from cuttings, so the use of a hormone rooting powder and a glass or plastic cover to retain humidity is recommended.

Climate

There are species suited to various climatic zones.