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. alba – White Willow – This very adaptable, fast growing spreading to columnar deciduous tree from Europe, North Africa and Western and Central Asia grows 80′ feet tall and 30′ feet wide. From gray-pink to brown shoots it carries lance shaped, saw toothed, slender pointed dull green leaves, to 4″ long, silky hairy when young, blue green beneath. The bark is a dark gray and deeply furrowed. Yellow male catkins, to 2″ long, or stalkless, yellow-green female catkins, 1 1/4″ long are borne in spring with the leaves.
var. caerulea – Cricket-bat Willow – English Willow – has upright branches and blue green leaves
Zones 4-9
