How long does it take for a Saguaro cactus to grow an arm?

The saguaro cactus is the largest cactus in the United States, and will normally reach heights of 40 feet tall. The tallest saguaro cactus ever measured towered over 78 feet into the air. The saguaro cactus grows as a column at a very slow rate, with all growth occurring at the tip, or top of the cactus. read more

Saguaro cactus babies grow under the protection of nurse trees. The cactus will continue to grow and often its nurse tree will expire. It is thought the cactus may cause the nurse tree to die by competing for resources. read more

A saguaro's arms usually begin to grow only after it is about 15 feet tall and around 75 years old. Despite what some may say, there is no limit to the number of arms a Saguaro can grow. read more