How old are the saguaro cacti in the park?
Saguaro (pronounced sah-war-oh) cacti, Carnegiea gigantea, only grow in the Sonoran Desert and are the largest cacti in the U.S. Growth rates vary depending on climate, precipitation, and location. The first branches or “arms” begin to appear when the plant is 50 to 70 years old. The saguaro grows slowly and a 10-year old plant may be less than 2-inches tall. A mature adult saguaro may be as tall as 40-50 feet, may weigh 6 tons or more, and is generally considered to be about 125 years old. The average life span of a saguaro is about 150 years.
