Description
Salix – Willow – Sallow – Osier –
There are about 400 fast growing, short lived dioecious, deciduous trees, shrubs, and subshrubs, in this genus. They have habitats ranging from lowland meadows and riverbanks, to sand dunes and mountain screes worldwide, except Australia, with the majority found in the Northern Hemisphere. They have usually bright green, simple, lance shaped smooth or with toothed edges, usually held alternately. They bear very small flowers in usually erect catkins, before or with the foliage. Of diverse form, willows are grown for their habit (especially the weeping willows) catkins (of which the males are most striking) and foliage and sometimes colorful winter shoots. The bark once used as a source of Aspirin is furrowed and scaly and the branches are used for basket weaving. The larger willows are suitable only for a large garden, those with a weeping habit are especially effective by water. Grow smaller willows as specimen trees in a small garden, shrubby willows in a shrub border, and dwarf willows in a rock garden or trough.
Grow in areas with clearly defined seasons in any deep, moist but well drained soil in full sun or part shade, willows dislike shallow alkaline soil. The dwarf and alpine species need gritty, sharply drained soil.
Prone to crown gall, canker, dieback, root knot nematode, powdery mildew, lesion nematode, mushroom root rot, tar spot, rust, twig blight, heart rot, caterpillars, borers, aphids, scale insects, and gall mites.
S. irrorata – Arizona Willow – This vigorous, upright shrub from Southwestern USA, grows 10′ feet tall and 15′ feet wide. From long shoots which are green at first becoming purple -yellow with a waxy bloom carry narrowly oblong, smooth or sparsely toothed edged, short stalked, glossy green leaves, to 4″ long, bluish-green beneath. In early or mid spring, before the leaves appear it produces gray catkins, to 1″ long. Male catkins have red anthers that age to yellow.
Zones 5-8
