Weeping willows can grow up to 100 feet tall and 75 feet wide. They are often near water—with branches drooping down to touch the surface—but also survive inland. The drooping branches are often brittle and break easily in the wind. To make them stronger, you must prune the tree properly. Knowledge of how to prune the weeping willow will help you keep branch loss in check and the tree healthy.
Choose the right time to prune your willow. These trees are particularly susceptible to diseases such as willow scab, black canker and various fungi. Pruning them in winter when they are dormant will reduce injury.
Disinfect your pruning shears by dipping the blades in rubbing alcohol. This will decrease the spread of disease between your plants.
Cut out branches infected with disease immediately. You don't have to wait for winter to do this. Gather the infected plant materials after pruning and throw them in the trash to stop the spread of disease.
Train your weeping willow when it is young to develop a strong structure. Prune away any competing trunks, so that there is one, strong leader. Also cut out branches growing from one spot or branches that are growing at an angle less than 45 degrees. Cut the branch right outside the root collar (the raised area where the branch meets the trunk).
Prune back drooping branches for pedestrian traffic as the trees grow older. Cut branches, on a mature tree, that grow less than 6 feet above the ground on the trunk. This will increase air circulation under the canopy and make your tree stronger.