Weeping willow trees have long, pendulous branches that sway with gentle breezes. The tree grows to heights of 45 to 70 feet and the spread is just as large. Weeping willows thrive in USDA hardiness zones 2 through 9a. Pruning keeps this tree looking tidy and helps develop a strong structure.
Prune the weeping willow branches so that they are approximately 2 inches apart during the winter months when the tree is dormant. This provides the proper air circulation to the tree. Do not prune upward growing branches on a weeping willow tree; they eventually will arch over and add height to the tree. The exception to this is if a mature tree forms a dense tangle of branches at the crown area. Leaving the tangle of branches results in the tree being top-heavy and susceptible to ice and wind storms. Pinch off any lateral growth as it appears, to keep the attractive appearance and shape. Trim any branches that touch the ground and prevent vehicular or pedestrian traffic. Remove small branches that rub or cross each other and then do the same with any larger branches. Maintain a balanced look at the crown area by trimming away any errant branches.
The root system of the weeping willow tree can grow to three times the distance from the trunk to the top of the canopy. They can interfere with mowing the lawn and even lift up sidewalks. It is best to plant this type of tree on the perimeters of your lawn area well away from any underground sewer or water lines or septic tank drain fields. They grow well near a river bank or a lake.
Sunlight and Soil Requirements
Weeping willows grow best in full sun. They tolerate most soil conditions, including loam, acidic, alkaline, clay and sand, as long as the area is well-drained. The tree does well in consistently moist soil. It can experience leaf drop in drought conditions.
Weeping willow trees can be quite brittle and have problems with breakage, particularly as they get older. It is best to stake the young trees in order to encourage a strong central trunk. The trees typically live about 30 years.