Willow grows from early March to mid-September, during which period it can grow inches per day in the right conditions. Planting is traditionally closely spaced, forcing the willow rods to grow straight and and tall to reach the light, which makes them ideal for basket weaving. It produces generous foliage during the growing season.
From mid-September to late November willow stops growing and gradually sheds its foliage. Between late November and early March willow is dormant and this is the season both for harvesting and for planting cuttings.
I grow 30 different varieties of willow for their bark colour, and weave some of this when freshly harvested. The remainder is allowed to dry out completely and is then resoaked prior to use.