The saguaro, Carnegiea gigantea, is the largest cactus in the United States and native to Arizona. In 1931 the opulent white blossom of the Saguaro Cactus was designated as Arizona’s state flower. The best time of year to see these cactus bloom is April through June.

The Saguaro cacti mainly grow in the Sonoran Desert of Arizona. When a Saguaro cactus reaches 35 years of age it begins to produce blossoms. Amassed near the ends of the branches, the green buds bloom into milky-white flowers. The Saguaro flower blooms after sunset and last only one day.

At the top of the flower tube is a compact group of yellow stamens. The saguaro cactus has more stamen on its flower than any other cactus. If conditions have been favorable for the Saguaro you could see hundreds of blossoms on a cactus.

Pollinators like birds, insects, and bats are attracted to the nectar that collects at the bottom of the flower’s 4 inch tube. A Saguaro blossom can only be fertilized by cross-pollination.

Only a few Saguaro flowers bloom each night and close by late morning; thus, giving a greater opportunity for pollination.

This elegant desert pageant occurs for about 2 months. From living in this area, we have to say it is hard to decide the exact dates but end of April to mid June would be notable.
bird pollinating the Saguaro cactus blossom

Pollinated flowers form a vivid red fruit filled with thousands of black seeds. The fruit is eaten and digested through which its dispersed throughout the desert.