Weeping willows (Salix spp.) have long drooping branches that often touch the ground. They grow 35 to 45 feet tall and have a broad rounded canopy. They are fast growing trees with brittle limbs that break easily during high winds. Babylon weeping willow (Salix babylonica) has the traditional weeping form of willows and is one of the most commonly grown varieties. "Aurea" has golden yellow branches; "Golden Curls" has twisted leaves and gold branches; "Crispa" has curled leaves.
Weeping willows prefer moist to boggy soil, but they will grow in drier areas also. They grow in full sun to partial shade. and need regular watering to prevent leaf drop during times of drought or high temperatures. Plant weeping willows after the predicted date of last frost in spring and at least 6 weeks before the predicted date of the first frost in fall. Avoid planting weeping willows during periods of hot weather or drought that will stress the trees and possibly kill them. Weeping willow branches are easy to root. Cut a branch 12 to 24 inches long, insert about halfway into moist soil, and keep evenly moist. The branches should root in 4 to 6 weeks.
Prune weeping willows in late spring or early summer to reduce the amount of sap produced by pruning cuts. Remove dead, diseased or damaged limbs, as well as those that interfere with passageways. Remove any limbs that grow upward on grafted trees. A swollen area or knot will be visible where the top of a less hardy variety of willow was grafted or joined to the roots of a hardier variety.
The roots of weeping willow trees are very aggressive and can extend up to 3 times the width of the canopy. They can grow into water and sewer lines, septic tanks, and drain fields. They grow bulges at and above ground level that can interfere with mowing and dislodge pathways, sidewalks and driveways.
Weeping willows are prone to numerous diseases, such as crown galls, fungal cankers, leaf spots, powdery mildew, root rots and willow scabs. Willows are host plants for gypsy moths and the larvae can decimate a tree in days. Other pests that attack Weeping Willows are aphids, borers, caterpillars and scale insects.
The leaves and bark of weeping willows contains salicylic acid, which it the base ingredient of aspirin. Chinese and Native American herbalists traditionally used the leaves and bark to treat headaches, toothaches, arthritis and fever.