A weeping form of pussy willow shrub (Salix caprea "Kilmarnock") is also sold or written as the variety "Pendula." This plant with drooping branches most often is grafted upon the stem of another plant to look like a small tree with twigs that architecturally weep to touch the ground. Thus, the mature height of the plant is determined by how high the graft union is on the trunk. Grow this weeping pussy willow in a sunny location in a moist, fertile, well-draining soil in USDA winter hardiness zones 4 through 8.
Prune away any dead, damaged and diseased twigs and branches from the weeping pussy willow any time of year it is noticed. Make the pruning cut with hand-held pruners 1/4 inch above a lower living/healthy branch junction, leaf or dormant bud.
Wait until late winter before conducting the annual trimming and structural pruning tasks on the plant. When leaves are absent, you can see the plant's structure well, and with spring a few weeks away, the plant will heal more quickly and soon send out new growth.
Trim back all weeping branch tips that touch the ground. Cut them back so that their tips are between 12 to 18 inches above the ground when the pruning is complete. Make the pruning cuts 1/4-inch above a dormant bud.
Look at the overall condition and shape of the canopy of the weeping pussy willow. Prune off any blatantly upright branches from the top of the plant. Make the cut to remove this upright twigs 1/4 inch above their connection to a lower, arching branch you wish to keep.
Step back as you make pruning cuts to ensure that you are maintaining an even, uniform shape on the weeping pussy willow. You can always come back later to further cut branches or remove them, so don't initially be overzealous and remove too much.
Examine the interior branching structure in the weeping canopy. Prune away any branches that are rubbing against each other, creating a wound where they rub. Remove any branches that awkwardly grow across the middle of the plant rather than emanating outward from the central trunk.
Look at the base of the plant trunk. Clip away any suckering shoots that are growing from it, as well as any twigs that are growing out from the trunk. These shoots are of the rootstock and genetically do not match the grafted weeping plant material on the top of the trunk. Make the pruning cuts as flush to the trunk as possible, but do not cut into or pierce the bark on the trunk.