World-Famous Saguaro Cactuses Are Losing Limbs, Falling Over in Lengthy Arizona Heat Wave

Saguaro cactuses are an iconic symbol of the American Southwest and the country's largest cactus species. But the world-famous cactuses are beginning to wither and die amidst the state’s record-setting summer heat waves.

Saguaro cactuses, which can grow 40 feet tall or higher, rely on summer monsoon rains in order to survive, but this year the storms have failed to materialize. As temperatures have soared to over 110 degrees Fahrenheit for nearly a month straight in Phoenix, the cactuses have begun losing arms, tilting to the side, and even collapsing entirely.

"These plants are adapted to this heat, but at some point the heat needs to cool down and the water needs to come," Tania Hernandez, a research scientist with the Desert Botanical Garden in Phoenix, told Reuters.

Scientists at the botanical garden, which houses nearly 70 percent of all cactus species, previously thought that cactuses were perfectly suited for Arizona’s balmy climate. However, they've recently begun studies which hope to determine exactly how much heat cactuses can tolerate.

In order to stay healthy, cactuses require rain or mist to cool down overnight. If they don't receive any natural water supply, they can suffer internal damage and slowly perish. It can take months, or even years, for plants suffering from prolonged heat exposure to actually die.

"We still don’t know if this is related to extreme heat and drought due to climate change, but we suspect that is the case," Hernandez said. She hopes the results of the garden's research will determine steps to move forward.

Saguaro cactuses grow only in the Sonoran Desert of America and Mexico. The plants have an estimated lifetime of 150-175 years, though some have been known to live over 200 years.

Last week, Arizona State Parks Tweeted a brief video showing the inner workings of a saguaro cactuses, which contain "15-20 woody ribs that support the immense weight of the columnar cactus as it soaks up and stores water."

If you have your own saguaro cactus that you’re hoping to keep alive and well this summer, the Desert Botanical Garden has issued some helpful tips.

“The best way to water your saguaro is to make a tree well around the base of the plant and run a hose with a trickle of water for four-six hours,” the garden recommends. “This will allow the water to reach deep into the soil (two-three feet) where the bulk of the roots are.”

Repeating this process once a month during the summer should ensure that your saguaro makes it to next season. It is essential, however, that you don't overwater your cactuses.