Saguaro cactus under threat: Arizona's warmer summers stress iconic plants; making them susceptible to disease

The heat and drought are taking a toll on Arizona's iconic Saguaro cactus. 

The symbol of the southwest may be in big trouble and scientists are scrambling to find answers. 

Icon of the southwest

Why you should care:

Giant Saguaros, an icon of the southwest. This majestic cactus is found only in the Sonoran Desert. 

But over the last five years, people are noticing more and more of them are leaning, rotting and dying. 

So what's happening, and why are Arizona Saguaros so stressed? 

What they're saying:

"The top just broke off. Right after that happened, the whole skin just sort of slid right off," says Scott Buck. 

Buck bought his Gilbert home because of the beauty of the three giant Saguaros in the front yard. 

Within the last three years, two have died. 

"It was just a black, tarry, smelly mess and one is starting to decay. There was just the black goo that came shedding off its skin," he said. 

Kimberlie McCue, Chief Science Officer at the Desert Botanical Garden, is seeing a similar trend.

"This is what's left of that, which was a very large Saguaro. It didn't just collapse, which is the normal thing that we used to see, it snapped," she said of a dead cactus in the sanctuary. 

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What we know:

The morbid trend has hit the Phoenix Desert Botanical Garden hard, where their family of about 1,000 Saguaros have recently been reduced to around 800. 

"In 2020, Saguaros started dying. It's definitely hotter than it used to be, consistently hotter in the summers than it use to be," she said. 

We had a hot, dry summer in 2020, 2023 was hotter and 2024 was worse. 

The hot temperatures put the cactus under stress, making their skin gummy and their insides more susceptible to disease. 

"A lot of Saguaros would drop an arm, also something we had never seen before," McCue said. 

Local perspective:

Corpses of giant cacti can be found across the state. 

Concerned by the current heat pattern we're in, scientists are thinking ahead, committed to replacing what the heat has killed off. 

"So what we have here on these racks under grow lights are many, many, many pots full of baby Saguaros that are being grown," she said. 

It will take years, but hundreds of these baby Saguaros will one day become giants. 

Big picture view:

Not all the cacti are dying. 

"But it's certainly a truth that even these beautifully-adapted desert plants have their limits."

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