Among the flowering trees of Arizona, the trees with pink and purple flowers are some of the most attractive, and also thrive well. These trees tolerate full sun and reflected heat, and are drought tolerant. They provide shade, wildlife habitat, improve air quality, and help conserve water by providing water storage and reducing storm run-off.
Desert Willow (Chilopsis linearis)
Chilopsis linearis, or desert willow, is a multi-stemmed tree with graceful appearance. It is common to find desert willows along the dry washes in the southwestern United States and northern Mexico, where they originate. The tree can grow up to 30 feet tall with equal spread. The leaves are simple, solitary, linear, long and weeping (like those of the willow tree), and measure one-half to 3 inches long and one-half to one-quarter inches wide. The leaves shed during winter.
From May through June, desert willows yield terminal clusters of fragrant, funnel-shaped, orchid-like flowers that range in color from white to deep pink. The flowers have distinctive yellow throat and venation. Flowering after June is sporadic. The flowers attract bees and hummingbirds. After blooming, long, narrow seed pods measuring 4 to 9 inches long tend to hang on the tree through the winter. Chilopsis linearis is hardy to 0 F.
Desert willows prefer full sun to light shade. They are drought tolerant, and require only supplemental or infrequent watering. Although tolerant to different types of soil, these trees do best in sandy washes and can handle rocky soil.
Texas Mountain Laurel (Sophora secundiflora)
Texas Mountain Laurel, also known as Sophora secundiflora, is a small, thornless evergreen tree that is native to North America. It can grow 15 to 25 feet with a spread of 10 feet. In its native habitat, Texas Mountain Laurel can reach up to 50 feet high. The dark green leaves are glossy, thick and leathery, measuring 2 inches long.
In early spring (from February to early March), the air is filled with the strong fragrance of grape bubble gum emitted by the blooming Texas Mountain Laurel. Large (2 to 5 inches long) pendulous, purple-blue, wisteria-like flowers appear densely among the glossy green foliage. White-flowered forms may appear occasionally. The tree produces hairy seedpods measuring 8 inches long that reveal bright red seeds when ripened. (The seeds are poisonous.) Deep, infrequent summer irrigation will encourage faster growth. Texas Mountain Laurel is very cold-hardy to at least 10 F.
Chaste Tree (Vitex agnus-castus)
Chaste Tree or Vitex agnus-castus, also known as Monk's Pepper Tree, is not a true tree but rather a multi-trunked shrub that slowly grows about 15 feet high in a tree-like form. Mature trees are about 25 feet tall and wide. Chaste tree originated from the Mediterranean and western Asia. It can tolerate hot summer heat, as well as temperatures below 0 F. While drought resistant, the chaste tree grows faster and looks lovelier when it's watered regularly.
Chaste tree produces long, narrow spikes of purple, fragrant flowers in the summer. The flower color can range from white to dark purple and covers long panicles that can elongate up to 12 inches. The flowers open from the bottom of the stem and continue up the stem within four to five weeks until the flowers completely cover the tree. The flowers attract bees, butterflies and hummingbirds. After blooming, the tree produces narrow spikes of round, dark brown seeds. As the flowers of summer fade, small dark purple berries follow.