Tree
Chitalpa
x Chitalpa tashkentensis · Bignoniaceae
Also called: Chitalpa, Pink Dawn chitalpa, Morning Cloud chitalpa
Chitalpa (x Chitalpa tashkentensis) is a moderate-water tree well suited to Tucson and the low desert. It grows to 20-30 ft H x 20-30 ft W in full sun, with a fast growth rate.
Chitalpa at a glance
- Water use
- Moderate (established)
- Sun
- Full sun (tolerates light afternoon shade in the low desert)
- Mature size
- 20-30 ft H x 20-30 ft W
- Growth rate
- Fast
- Bloom
- Pink to white (catalpa-like, frilled trumpet flowers); 'Pink Dawn' pink, 'Morning Cloud' pale pink to white, Late spring through fall (May-September), in showy upright clusters at branch ends
- Cold hardiness
- Cold hardy to about USDA zone 6 (roughly -10 F); very cold tolerant. Deciduous.
- Soil
- Adaptable; prefers well-drained soils but tolerates a range including clay and alkaline soils. Good drainage reduces root/disease problems.
- Native range
- Not native; an intergeneric hybrid (Chilopsis linearis x Catalpa bignonioides) first bred in Tashkent, Uzbekistan in the 1960s and introduced to the U.S. in 1977.
- Best used as
- Flowering shade/accent tree, Patio, lawn, and streetscape tree where extra water is available, Showy summer-blooming specimen
- Wildlife
- Trumpet flowers attract hummingbirds, bees, and butterflies. Being sterile, it produces no seed and so offers little seed-based wildlife food.
- Toxicity
- Not known to be significantly toxic to humans or pets.
How to grow Chitalpa in Tucson & the low desert
Watering
Needs more water than its desert-willow parent in Tucson; provide regular deep irrigation roughly every 7-14 days in summer heat. Insufficient water causes leaf scorch and marginal burn; it is the thirstiest tree on this list and not a true low-water plant in the low desert.
Fertilizer & nutrients
Low to moderate needs; a light application of balanced or slow-release fertilizer in early spring supports vigor and bloom. Avoid excess nitrogen.
Pruning & care
Prune in late winter dormancy to develop strong structure and remove crossing/weak wood, since the hybrid can form included bark and weak crotches; thin to improve air circulation (helps limit powdery mildew and dieback). Sterile flowers set no seedpods, so cleanup is minimal.
Notes
Sterile hybrid (no seedpods), giving a cleaner habit than catalpa or desert willow. Faster-growing and more cold-hardy than desert willow but distinctly higher water use and prone to powdery mildew, verticillium/branch dieback, and weak-wood breakage, especially when stressed by heat and underwatering. Better suited to higher-water or transition zones than to true xeric desert plantings; site with afternoon protection and adequate irrigation in Tucson.
Sources: Missouri Botanical Garden Plant Finder; Oregon State University Landscape Plants; University of Arizona Cooperative Extension; Pacific Horticulture