Saguaro
The tall, arm-raising cactus of the Sonoran Desert, found in the United States mainly around Tucson at Saguaro National Park.
Saguaro at a glance
Carnegiea gigantea suh-WAR-oh; Carnegiea gigantea is kar-NEG-ee-uh jy-GAN-tee-uh
- Type
- Plant · cactus
- Diet
- Producer
- Size
- A full-grown saguaro stands about 40 feet tall, roughly as high as a four-story building. Soaked full of water after a storm, a big one can weigh more than 3,000 pounds, about as much as a small car.
- Lifespan
- Around 150 to 200 years for a healthy desert saguaro.
- Conservation
- Least Concern
Eats sunlight, rainwater, carbon dioxide, soil nutrients
A saguaro makes its own food by photosynthesis, using its green skin instead of leaves to catch sunlight. When rain falls, it soaks up as much water as it can and stores it inside its pleated body, then lives off that water through the long dry months.
Is it safe to touch?
A saguaro is covered in stiff, sharp spines up to a couple of inches long, so the rule is look, do not touch. Do not push on it, lean on it, or try to climb it. It is also protected by law in Arizona, so never cut or carve one. Enjoy it from a step or two back.
The saguaro is the tall, arm-raising cactus that stands over the Sonoran Desert, and in the United States it grows mainly in southern Arizona, around Tucson, at Saguaro National Park. A full-grown one reaches about 40 feet, roughly as high as a four-story building. Instead of leaves it has green skin that does the work of photosynthesis, turning sunlight, water, and carbon dioxide into sugar. Its whole body is built to hold water. Accordion-style pleats let it swell up like a giant tank when rain falls, and a big saguaro soaked full after a storm can weigh more than 3,000 pounds, about as much as a small car, then live off that stored water through the long dry months.
A saguaro takes its time. After ten years it may be only a few inches tall, and it usually does not grow its first arm until it is around 75 to 100 years old, so a saguaro waving several arms has already stood in the desert for more than a century. Healthy ones live around 150 to 200 years. Along the way the cactus becomes an apartment building for the desert: Gila woodpeckers and gilded flickers drill nest holes in the trunk, and after the birds move on, other animals move into the old holes. Owls, hawks, and bats all use the saguaro through its long life.
The desert around the saguaro is the homeland of the Tohono O’odham people, who each June harvest the ripe red fruit from the tops of the cactus using a long pole, cook it into syrup and jam, and mark the start of their traditional new year with the harvest. The saguaro is common enough that the IUCN lists it as Least Concern, and it is protected by Arizona law. For a visitor the care is simple. It is covered in stiff spines up to a couple of inches long, so look, do not touch, and never lean on it, climb it, or carve it.
Did you know?
- A saguaro grows very slowly. It may be only a few inches tall after ten years, and it usually does not grow its first arm until it is around 75 to 100 years old, so a saguaro with arms is older than most people.
- A saguaro is like a giant water tank. Its body has accordion-style pleats that swell up when it drinks after a storm, letting one big cactus hold hundreds of gallons of water.
- The Tohono O'odham people, whose homeland includes this desert, harvest the ripe red saguaro fruit each June using a long pole. They cook it into syrup and jam, and the harvest marks the start of their traditional new year.
Common questions
How tall does a saguaro get?
About 40 feet, as tall as a four-story building. They grow very slowly and can take 100 years to reach that height.
Why do saguaros have arms?
The arms grow after the cactus is about 75 to 100 years old and help it make more flowers and fruit. A saguaro with lots of arms is very old.
Can you touch a saguaro?
No. It is covered in sharp spines and is protected by law. Look at it closely from a step back, but never touch, push, or climb it.
How does a saguaro hold water?
Its body has folds like an accordion that swell up when it drinks after rain. One large saguaro can store hundreds of gallons for the dry months.