Guest author Dan Songster contributed this article featuring the Desert Willow tree as the Plant of the Month for July.

Desert willow-Chilopsis linearis

• Plant Type: Large deciduous shrub, most often used as small tree
• Light: Full sun (the hotter the better)
• Soil: Adaptable
• Water: Adaptable

A favorite in the garden all summer long, this fast-growing plant (12-30 feet) may be the showiest blooming native tree California has to offer. Its one- to three-inch-wide flower clusters are displayed on branch ends. The flower colors range from white to pink to lavender, and also burgundy.

The typical flower of this species is funnel-shaped and colored a light “orchid” pink with a creamy-colored throat and yellow bands leading inward. These fragrant flowers put on a big show in early summer with waves of bloom often lasting through the fall.

By October, the flowers are often replaced by slender seedpods, 6-10 inches long. Desert Willow has a winter dormant period that is long, but it is still attractive with its leaning and twisting dark trunk and open spreading crown making for a lovely silhouette–almost sculptural in nature.

Design

In larger gardens, if placed in sunny spots away from competing shade of large trees or buildings, it can quickly get fairly large (25 feet plus in some cases). As you might imagine it can easily be the focal point of a native design.

Desert Willow trees can be especially useful in small gardens. Consider one planted near a patio where it attracts hummingbirds, large bees (like the Carpenter and Bumble Bee), and butterflies for closeup views.

When in leaf, Desert Willow trees provide light, airy shade. In winter the loss of leaves means more sunlight filtering through its branches. Its relatively small size means it can fit in the space along sidewalks with minor pruning of side branches, and when in bloom neighbors will invariably ask what that incredible small tree is. In summary, this is a very versatile tree for your garden! 

Some obvious plants to use around this could be plants from a desert environment like Brittlebush (Encelia farinosa), Desert Lavender (Hyptis emoyri), and any of the Apricot Mallows (Sphaeralcea ambigua). Other fitting companion plants could include anything low- to mid-size that fits beneath and near the tree and does not mind a bit of light shade in summer. These can range from various Penstemon, Sage, Encelia, Buckwheat, and even Ceanothus. 

Care

The California Flora Nursery website advises: “Avoid cool coastal conditions and heavy wet soils. Grows fast when happy with no pest or disease problems, demanding little.” True, not much maintenance is needed although light pruning to direct growth when the plant is young will help create an intriguing shape. Removing young water sprouts near the base helps it become more “tree-like”.

Desert Willow’s natural structure is a low branching form (multi-trunk looking) that is graceful and appealing to most gardeners.

Bert at Las Pilitas nursery says, “It can be pruned to make a weeping willow effect. (A weeping willow with big pink-purple catalpa-like flowers!)” Artful pruning will accentuate its whimsical shape but attempting to trim it into a standard upright or formal shape would certainly work against the plant’s graceful tendencies.

Visit mature trees in gardens and learn how they grow–this will help you decide which branches stay or are removed, and for that matter, where in your garden they might fit best.

Watering

Once established, this tree can survive on rainfall alone, but supplemental irrigation during the summer will produce more attractive foliage and longer lasting flowers. Although it may prefer well-drained soil (think of its home in desert washes), it accepts most soils–yes, even thriving in clay soils. It seems its only requirements for sure success is not soaking it in clay soils, and making sure it has sunshine–lots of sunshine. 

Cultivars

Besides the outstanding straight species of Desert Willow, many cultivars have been selected with varying flower colors, leaf sizes, and amounts of seed pods. A few of these are:

• ‘Bubba’ with dark violet flowers
• ‘Burgundy’ with dark wine red flowers
• ‘Lois Adams’ with crepe-textured violet flowers that produce few if any seedpods
• ‘Art’s Seedless’ another without seedpods
• ‘White Storm’ with white flowers
• ‘Hope’ with white flowers
• ‘Warren Jones’ semi-evergreen with gray-green leaves and very pale pink flowers
• ‘Regal’ with large, bi-colored flowers that are pale lilac above and rich purple below
• ‘Maggie’s Pink’ named in honor of Maggie Olsen, long-time dependable and cheerful assistant to our friend Greg Rubin of California’s Own Native Landscape Design.

The flowers of ‘Maggie’s Pink’ are a deeper shade of pink than the straight species and lighter than the variety known as ‘Burgundy.’ It is richer green, and may hold its leaves (and its bloom) longer than some other cultivars. This horticultural selection was made by Greg Rubin and the plant was introduced by Moosa Creek Nursery in 2016.

Despite its common name, Desert Willow is not a real willow of the Salix genus–it just has long, narrow leaves like a willow. It is actually related to the Catalpa tree.

Charlie McDonald of the U.S. Forest Service states the obvious,

“Sometimes plant names are just plain confusing. The desert willow is not a true willow, but it does grow in deserts. Desert willow is in the trumpet creeper family (Bignoniaceae), which has many showy-flowered species found mostly in the tropics.”

Do you have a Desert Willow growing in your garden? Send a reply and share your experience with this lovely accent tree.