The weeping willow is probably the best known of the weeping trees, with gracefully arching stems that dangle delicately and shiver in the breeze. They make a great focal point in landscaping and add an elegant touch to a yard. The leaves of Salix babylonica are lance-shaped and grow three to six inches long; they turn yellow in the fall before dropping. The weeping willow's bark is rough and gray, with long, deep ridges. When the tree blooms in late winter or spring, yellow catkins (flowers) appear. Weeping willows are fast-growing trees, adding up to 10 feet per year when young, but its average lifespan is a relatively short 30 years.
- Botanical name: Salix babylonica
- Common name: Weeping willows or Babylon willow
- Plant type: Deciduous perennial
- Mature size: 35 to 50 feet tall with an equivalent spread
- Sun exposure: Full sun
- Soil type: Rich and moist
- Soil pH: Slightly acidic
- Bloom time: Late winter, spring
- Flower color: Yellow
- Hardiness zones: 4 through 10
- Native area: China
How to Grow Weeping Willows
Because weeping willows can reach 50 feet in height and width, they need a wide swath of lawn or yard to stretch into. They work well in areas that are naturally quite moist, but they tend to shed a lot of leaves and twigs so avoid planting them where falling branches can cause damage or injury. These specimens also should not be planted near sewer, septic tanks, or water lines: Their root systems are aggressive—sometimes stretching wider than the tree is tall—and not only do they seek out the nearest and most abundant source of water, but they are attracted to the nutrients in the soil around a septic system, as well as the oxygen in the drainage lines.
Full sun and partial shade are best for this tree. It needs at least four hours of direct, unfiltered sunlight each day.
This tree is tolerant of a wide variety of well-draining soils and soil pH. Although it prefers moist, slightly acidic soil, it grows well in alkaline, loamy, rich, sandy, and clay soils. If your soil is too alkaline, add some organic matter to lower the pH.
Willows like standing water. The long, far-reaching root system can be helpful in clearing up puddle- and flood-prone areas of a landscape. They also like to grow near ponds, streams, and lakes.
Temperature and Humidity
Weeping willows have some drought tolerance and can handle the winter cold. The tree can also tolerate summer desert heat as long as greenery and water are not too far away.
A mature weeping willow does not require fertilizer if it is planted in rich soil and its leaves are a healthy green or nearby lawns are fertilized regularly. However, you can supply fertilizer to support lush growth.
A balanced fertilizer with an equal ratio of nitrogen, phosphorus, and potassium (such as a 20-20-20 formula) is appropriate for a weeping willow. Nitrogen supports foliage growth on the tree's long, weeping branches. Phosphorus supports the growth of roots, stems, and flowers. Potassium encourages overall health. If you plan to use organic fertilizer, steer manure is a good choice. It is a balanced combination of the main nutrients nitrogen, phosphorus, and potassium.
Propagation of Salix babylonica is through stem cuttings. Make sure the cuttings are at least two feet long. Cut at the base and take from mature weeping willows when the trees are dormant, meaning after leaves have fallen in autumn and temperatures are consistently below 32 degrees Fahrenheit at night. Cuttings can be placed directly into the soil in late winter or early spring. Keep the soil moist throughout the growing season to allow the cutting to develop healthy roots.
While the tree is young, prune it so that there is only one central leader. It should also be trained to have wide branch crotches to help prevent breakage, as the tree is somewhat brittle and can be susceptible to wind damage. It is a good idea to prune a weeping willow in February or March, snipping back all its branches. This will trigger the sprouting of new branches and will give the tree more vigor.
Common Pests and Diseases
Weeping willows can be struck by several pests, including the gypsy moth, aphids and borers. These insects are difficult to control—especially on large trees—but targeted spraying can help. Young weeping willows are also tempting to deer, elk, and rabbits; place a collar around young trees to protect them from wildlife.
This tree may be affected by willow scab, crown gall, willow blight, black canker, fungi, cankers, leaf spot, tar spot, powdery mildew, rust, and root rot. Symptoms include branch or twig dieback and defoliation but in some cases, the disease can kill the tree. Plant disease resistant trees and provide adequate water to keep the tree healthy, since healthy trees are better able to fend off disease. Rake up and remove leaf litter promptly, to control the spreading of disease.
Varieties to Grow
Although this tree is the most common in landscapes, there are some related species to consider:
- Golden weeping willow (S. alba "Tristis") has golden twigs. It grows in zones 3 through 10 to a height of 50 to 70 feet tall and wide. Its green leaves turn golden in fall, adding autumn interest.
- Wisconsin weeping willow (S. babylonica x S. pentachdra) grows quickly to 30 to 40 feet tall and wide. For a weeping willow with even longer pendulous branches, try the cultivar "Elegantissima." Both types grow in zones 4 through 9.