The majestic saguaro is an icon of the southwestern desert. I love this cactus. They each seem to have a different personality. There are some that are tall, with little or no arms. They look like desert sentinels, standing guard over their domain. Others are more comical, with arms going this way and that, as if they are laughing at some cosmic joke.
The saguaro is the largest cactus in the United States and can only be found in the Sonoran Desert (southern Arizona, southeast California and northwest Mexico). It likes the hot and dry climate and only grows below 3500 feet in elevation.
The size of the trunk can be up to two feet in diameter, they can grow up to 60 feet tall, have as many as 25 "arms" and can live up to 200 years. The cactus doesn't need a lot of water to survive, but when it does rain, its ribs expand and it swells up to store as much water as it can. When fully saturated a full grown saguaro can weigh as much as 5000 lbs. The saguaro is a slow growing cactus and may only be a few inches tall after 10 or more years of life.
In order to live in the hot, dry Sonoran Desert, the cactus has developed a unique root system. It has one main tap root, that extends about three feet downward. All of the other roots extend radically outward from the cactus. These are only about 4-6 inches below the ground, but are about as long as the cactus is tall. Think of the root system as a large wagon wheel, with the saguaro as the hub. This is an efficient system to pick up water and keep the cactus from blowing over in a storm.
The saguaro has a strong internal framework of ribs. When the saguaro dies, the fleshy outlayers decay, leaving only these internal ribs. These are beautiful and strong in their own right and have been used by people for centuries for building material and ornamental items.
Some saguaro have "holes" in them. Gila woodpeckers hollow out nests (sometimes making a few of these before selecting one) in the soft tissue. The saguaro "repairs" these holes with callous scar tissue so they don't lose water. It makes a perfect nest for the woodpeckers and owls. These are called "saguaro boots" and can be found among the dead saguaros. Native Americans used these as water containers long before canteens were invented.
Although the saguaro is not currently listed on the endangered species list, Arizona has strict regulations governing harvesting, destroying or collecting the cactus. Saguaros are in danger as their skin darkens prematurely, a condition known as "the brown decline". Poachers represent another dangers for saguaros because they are sought-after plants in residential gardens. Please don't do anything that would destroy these beautiful, majestic sentinels of the desert!
Click here for more information on saguaros and the ongoing dangers they face.