Saguaro’s are the tall picturesque cactus, and you will only see them in the Sonoran Desert. They are home to the Gila Woodpecker and Red Flicker, owls, bats, insects and even hawks. Saguaro’s store thousands of gallons of liquid, and can weight several tons depending on the number of arms they have and how much it has rained. They are slow growing and long living cactus, with an average life span of about 250 years. They are about 90% liquid and can retain thousands of gallons of water. The pleats up and down the cactus allow it to expand and store more water. Saguaro’s grow their arms around 75 years (for additional water storage), and start flowering around 50 years (about 5 to 7 feet tall).
The cactus flowers are Arizona’s state flower, and a valuable food source for the migrating Lesser Long Nose bats. They flower for about two to three weeks between May and June, and will eventually produce fruit. The fruit contains thousands of tiny black seeds surrounded in a reddish pink pulp. The pulp supplies food many animals, including bats, and in turn, the animals spread the cactus seeds in their dropping which helps the Saguaro propegate.
Young cactus are especially prone to freezing in the winter months, and will typically start growing under trees and shrubs looking for shelter from the cold. Saguaro’s have an impressive root system containing a tap root, which is about 4-5 feet long, and an intricate system of radial roots. These radial roots lay about 2 inches beneath the ground, and extend out from the cactus as far as the cactus is tall. These roots usually cover up the roots of surrounding vegetation, and will typically kill off the “nursing” plant that allowed the cactus to live.
Hohokam Indians believed that the Saguaro’s were their ancestors, and respected these large cactus with the belief that Saguaro’s were their ancestors. Actually, people were living in this region (Sonoran Desert) before these cactus were. As the ice age ended, southern regions became extremely hot while northern areas started to warm up. Humans, plants, and animals began to migrate North in search of more suitable temperatures. The plants were the slowest to migrate, and arrived in the Sonoran desert after humans did.
When the saguaro finally dies, it will fall over and begin to decompose. This happens rather fast as the stored water evaporates quickly under the desert sun. Many insects use these fallen cactus as precious and valuable sources of water, especially during the dry seasons. Unfortunately, the stored liquid found in the Saguaro’s is extremely toxic to most mammals. Eventually the Saguaro “deflates’ as the water disappears, and the spines and green skin starts to decompose. Over time, the internal skeleton of the cactus can be seen. Saguaro skeletons are composed of long ribs of wood that run the length of the cactus, bottom to top, and through their arms. The skeletons provide an excellent habitat to many species of animals and insects.
Saguaros are an integral part to the delicate eco system found in the Sonoran Desert. As with all native plants and cactus in the Sonoran Desert, they are protected under the Department of Agricultre’s Arizona Native Plant Law.