Botanical name: Chilopsis linearis
Range: Dry washes between 1,500 and 5,000 feet throughout the Southwestern United States and Northern Mexico
Desert willow is not a true willow but with its long, slender weeping leaves it's a better substitute than the willow for the arid southwest region. A fast growing tree, it can grow 2-3 feet a year and reach heights of 30 feet. By nature it's a multi-trunked tree but can be pruned into a single trunk specimen or grown as a small shrub. Because it lacks thorns and the roots are not invasive, it can be planted close to walls and paving without causing structural problems.
The flowers are fragrant, orchid-like and hang in clusters of five or more and range from white to pink to purple. Blooming from April to late summer the flowers are frequently visited by hummingbirds and butterflies. Desert willow is deciduous and the 8 inch seed pods will hang on the tree through the winter sometimes giving it a "shaggy appearance." The pods may be trimmed off, but consider leaving them on to provide food for birds. Inspection of a pod will reveal slender seeds with "hairs" on it. Hummingbirds use this to build nests with.
Desert willow prefers full sun but can take partial shade. Tolerant of drought, heat, wind, and cold, once it becomes established it can survive on rainfall alone. A deep watering once a month during the hot season will keep it more attractive looking. Discontinue irrigation in early fall as new growth can be damaged by frost. Thinning and shaping is best done in early summer. Seeds need no pretreatment for germination and desert willow are very easy to grow from seed. Because it has a very long tap root, I find it easier to start them in one gallon buckets. Plants will bloom the first year.
A related species, Chitalpa, Chitalpa X tashkentensis, is a hybrid of the desert willow and catalpa. Taking the best of both worlds, it matures at a height of 25 feet with a rounded canopy of stout branches. The leaves are dark green, an inch wide and three inches long which produces denser shade than the desert willow. The flowers are larger, bloom profusely, and are sterile so does not produce seed pods and gives it a cleaner appearance in winter. Tap rooted like it parents, it can also be planted near structures and shares the same tolerances of harsh desert conditions.
Chilopsis linearis - grow a grove of them!