Family: Salicaceae
Common Name: Willow

Occurring in cold and temperate regions of the northern hemisphere, including most northern European countries, this genus consists of around 300 species of deciduous trees and shrubs. The alternate, bright green leaves are generally slender and lance-shaped. The small flowers are borne in fluffy catkins, the male being yellow and the female, green and less conspicuous. Grown for their timber, willows also make attractive ornamentals or specimens, particularly in areas where drainage is poor, and have a great range of traditional uses in farming and gardening. Fast-growing, they have tough vet flexible stems that are used in basket-weaving. Shrubby willows with brightly coloured stems are often grown for winter effect.

Species

S. alba, white willow, zone 2, from Europe and central Asia, is an elegant tree, to 25 m (80 ft), its branches weeping at the ends. The silky foliage is blue-green on the under-sides. It makes a good windbreak. Cultivar 'Aurea' has yellow-green branches; var. caerulea is the cricket bat willow, valued for its timber, which is used to make cricket bats; subsp. vitellina, the golden willow, has golden yellow stems; and subsp. vitellina 'Britzensis' has brilliant orange-red young stems.

S. babylonica, weeping willow, zone 5, from China, may be confused with S. alba 'Tristis', the weeping species now often cultivated. A graceful, weeping tree with long, slender leaves, it grows to 15 m (50 ft) or more.

S. babylonica var. pekinensis 'Tortuosa' has twisted and curled shoots and stems that show up particularly well in winter. The leaves are also twisted. It makes an unusual specimen tree for a lawn, and grows to 15 m (50 ft).

S. caprea, pussy willow, zone 5, grows well in poor drainage areas but its extensive root system may he a problem. It grows to 8 m (26 ft), the leaves being oval in shape. The attractive, silky male catkins make the leafless twigs popular for indoor decoration. The cultivar 'Kilmarnock', known as the Kilmarnock willow, is a very popular, small, weeping tree growing to a height of 2 m (6 ft), with a similar spread. It is ideal for small gardens.

S. cordata, furry willow, zone 2, grows to 2.5 m (8 ft), with silky leaves and long, slender catkins.

S. fragilis, crack willow, zone 5, from north-western Asia and Europe, is one of the larger species, growing to 20 m (65 ft) or more, its brittle branches forming a broad crown. The toothed leaves colour yellow in autumn.

S. lanata, woolly willow, is a shrub, to 1 m (3 ft), with silvery foliage.

S. purpurea, purple osier, zone 5, is one of the best known of the shrubby species, growing to around 5 m (16 ft). The leaves are blueish green, the young shoots reddish purple, and the catkins silvery green.

S. x sepulcralis var. chrysocoma, golden weeping willow, zone 6, is widely grown. The young shoots are deep yellow and hang right down to the ground. It is a large tree, with a height and spread of about 15 m (50 ft).

Cultivation

Willows are easy to grow, most species preferring moist, heavy soils. All species do well near water or in poorly drained areas. Some benefit from stooling or pollarding annually to encourage the attractive stem or branch colouration. Propagate from hardwood cuttings, which can be quite long young stems, and root outdoors in moist soil; 30-40 cm (12-16 in) soft tip cuttings will root readily in water. Larger growing species should not be planted near buildings or drains as the roots are extremely vigorous.

Climate

There are species suited to various climatic zones.