Cactuses grow in all of the desert areas of the United States, putting on beautiful displays of flowers primarily in spring or summer. The plants fall into the succulent group since they store water in their leaves or stems. A variety of cactuses make great plants for the garden as long as they do not receive too much water but get plenty of sun.
Cactus range in size from a few inches to more than 40 feet tall. Many of the cactuses produce beautiful, brightly colored flowers meant to attract pollinating hummingbirds and other insects. Flowers range in color from the bright pink of the hedgehog cactus to the deep reds of the prickly pear cactus. The saguaro features bright white flowers similar to sunflowers. On most flowering cactuses, fading flowers often produce fruits with lots of seeds.
Cactus flowers occur in all of the American deserts, including the hottest desert, the Mojave Desert located in southeastern California, and the largest desert, the Great Basin Desert located in Nevada. Two other major deserts are the Sonoran Desert and the Chihuahuan Desert, both located in the Southwest. Several smaller deserts in Colorado, Idaho, Washington, Arizona, Texas, Wyoming and Oregon also support cactuses of varying types.
Most cactuses offer a profusion of blooms, but a few seldom bloom, making their flowers a cause for celebration. Agave cactus falls into this category. The plant makes a great choice for gardens, especially for open areas, where it flourishes for years without blooming. Then suddenly, beautiful whitish-yellow flowers bloom just once on this plant, usually toward the end of the plant's life.
Another cactus, the night-blooming cereus, blooms on only one night a year. Cereus looks like a dry, dead bush most of its life. But on one summer night each year, a fragile, trumpet-shaped flower full of fragrance opens during the night. By morning, the flower closes up forever.
Cactus flowers play an important role in the survival of wildlife and birds. The flowers of the agave cactus provide nectar for bats and hummingbirds. Insects on the flowers also attract birds. Javelina eat the young flower stalks. Nectar and pollen from the saguaro cactus flowers also are eaten by bats and birds.
Some types of cactus grow well in gardens, giving these areas unusual focal points when the cactus produces blooms. Their drought-tolerance also makes cactuses highly desirable since they require little watering or other maintenance. After the flowers fade, some cactuses produce delicious, edible fruits such as the prickly pear. Prickly bar branches are sold as a vegetable in some stores.
Native Americans found many uses for cactuses and their flowers. The century plant, a cactus growing in the Sonoran and Chihuahuan deserts, produces six-petaled yellow flowers that bloom from June through August. They grow up to 40 feet in height, and Indians used the entire plant to make soap, food, medicine and weapons.