Occasionally, aphids, scale, and Japanese beetles are a problem, and powdery mildew and rust diseases also sometimes appear. In every case but the Japanese beetles, pruning to the ground in spring after flowering reduces or eliminates the pest. Even normal pruning will usually rejuvenate the plant. However desirable for the above reasons, heavy annual pruning may also produce a somewhat rangy-looking plant. If your willow is positioned in a prominent location, so that appearance is important, prune out a third of the oldest wood each year.
Older wood is more susceptible to disease and pest problems.
Prune just before the leaves come out, in late winter or early spring. It's easy to propagate willows by cuttings. Start with an 8-inch leafless section of stem in spring. Plant it in a 4-inch pot filled with moist potting soil, then place it in a cool, shaded location. As soon as roots emerge from the pot's drainage hole, plant it in a permanent location or transplant to a larger container.