Weeping willows make spectacular trees in the right location. Their weeping, graceful form softens a landscape and looks attractive near ponds and lakes. Willows tolerate a wide range of growing conditions and soils, including clay soils, but they do have some potential liabilities. Most willows are large trees, best reserved for open areas rather than residential lots.
Willows grow best in full sun and moist soil, but they adapt to a variety of conditions, including clay, sand, alkaline and acidic soils, and drought conditions. They even survive periods of extended flooding next to streams or inlets.
Willows are fast-growing trees that are prone to branch breakage and trunk rot. They rarely live more than 30 years and the falling branches create lawn litter after rain or wind. Willows have shallow, invasive roots that plug septic systems or sewer lines if planted too closely to the house. These roots may also damage sidewalks and patios and create lumps in the yard.
Many willow varieties grow 50 feet or more, making them impractical for small lots. If you have the space, though, try Babylon willow, an attractive large tree with fine leaves and sweeping limbs. Babylon willow is only hardy to U.S. Department of Agriculture plant hardiness zone 6. In Northern regions, try Thurlow weeping willow or white willow. Dwarf willows or pussy willows are suitable for small yards and also tolerate clay soil.
Willows will grow well in clay soils, especially in mild climates, where high winds and fierce storms are less likely. Plant a slow-growing, long-lived tree nearby, though, to take the willow's place in years to come.