With its blazing hot summers and temperate winters, the arid Phoenix climate is too harsh for many flowering trees. However, there are a surprisingly large number of heat-loving, drought-tolerant flowering trees that have adapted to the desert environment and will provide color, variety and even much-welcomed, cool shade to the landscape.
Yellow oleander (Thevetia peruviana) loves hot weather and sunshine and will grow next to patios or hot masonry walls, making it ideal for Phoenix's desert growing conditions. Yellow oleander can grow to heights of 18 feet but usually is limited to 6 to 8 feet. It has a pleasant, rounded shape. A quick-growing tree, yellow oleander is well-suited for mass planting or privacy hedges. Yellow oleander often blooms year-round with showy, fragrant, 2-inch yellow or orange blooms.
Carob tree (Ceratonia siliqua) is a rugged evergreen that can grow as tall as 50 feet at maturity. With its dense canopy of thick, green leaves, the carob is one of the best trees for casting cooling shade in areas with limited water. The reddish blooms, which appear from September to November, emit a musky fragrance that some people find unpleasant. The dark brown carob tree pods are several inches long and filled with a seed that often is used as a substitute for chocolate. Although the carob tree can grow in poor, rocky soil, it needs full sunlight in order to thrive.
Purple Orchid Tree
The purple orchid tree (Bauhinia variegata) is a hardy, drought-tolerant, heat-loving tree that will brighten up the desert landscape with stunning pink, purple or white orchid-like flowers in March and April. When the flowers fade, the blooms will be replaced by slender, 12-inch seedpods that usually will remain on the tree until the following spring. Purple orchid is a mid-size tree with a round shape that will grow 20 to 35 feet at maturity. The purple orchid prefers full sun to light shade.
Russian olive (Elaeagnus augustifolia) can grow up to 6 feet per year to a mature height of 12 to 40 feet, depending on the available water supply. Although Russian olive likes to be planted in shady areas, the tree can tolerate Phoenix's blazing hot 110-degree F summer days. In early summer, Russian olive will produce masses of fragrant, creamy yellow blooms, followed by small, olive-size, orange-grown fruits.
Feather bush (Lysiloma watsonii), native to the Mexican desert, is a graceful, slow-growing tree that will reach maximum heights of 20 feet. Feather bush, with it's lacy green foliage, is no stranger to hot, dry desert climates, and should be planted in full sunlight. In May and June, feather bush, also called fern of the desert, will produce small, creamy-white puffballs. Although feather bush provides moderate shade, it isn't a good choice for a patio or pool area, as the tree covers the ground with spent leaves and flowers throughout much of the year.