I have a dwarf variegated willow tree and need to trim it. When is the best time to prune without damaging the tree?
There is an old saying that the best time to prune is when your equipment is sharp and in your hand. There is a certain amount of truth in that statement. However, there are several factors that may determine the best time to prune a variegated willow tree. Essentially, light pruning on side branches to retain shape can be done about any time. The preferred time, however, is late spring or early summer.
Any heavy pruning or thinning cuts should be made when the tree is dormant in late winter or early spring, before new growth starts. Dormant pruning causes less stress to most trees. Try to avoid pruning in late summer or fall because new growth may be stimulated and dormancy delayed. Late new growth may be more susceptible to winter injury and permanent damage.