How climate change may be affecting saguaro cactus

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The Saguaro cactus could be at risk from climate change and pollution, especially in metropolitan areas. Researchers at the Desert Botanical Garden are looking into the effects of this.

Arizona Horizon heard from Kevin Hultine, director of research at the Desert Botanical Garden, for more information.

What’s Happening?

With temperatures reaching over 100 degrees, the effect the hot weather has on plants is great.

“We got a lot of reports of Saguaros falling over and arms falling and that was really an indication of the impact heat stress is having on Saguaros.”

Normally, even with little water, plants can conserve water when it is hot outside. But with the extreme temperatures that occurred back in 2020, the heat caused plants like Saguaros to lose their structural integrity.

This would leave dead saguaros standing and many of them had multiple arms falling off.

“There’ll be a really intense drought or heatwave and sometimes we don’t see the full effect of that until several years later…unfortunately we may still be seeing that impact from two years ago.”


To help understand the effects and gather information, the Desert Botanical Garden is working on a database headed by Dr. Tania Hernandez. Citizens can upload information like photos or notes about Saguaros in the area.

“Over time, this provides us with literally a database to understand how some of these Saguaros are changing in terms of their health and the way they look…and about what and when these Saguaros are actually being impacted by changing weather conditions.”

Some of the warning signs of a Saguaro that has been affected by the temperature negatively is usually yellowing around the base or top of the cactus.


Low elevation is considered to be a bad habitat for Saguaros. Those in the Cave Creek area and around can be seen as healthy. But the Saguaros within the metro area and the city are not getting the kind of elevation necessary for their living conditions.

Many of the Saguaros in the city have been transplanted, thus making it more difficult to keep them alive.

“One of the challenges is getting the entire root system. Saguaros, unlike most cactus plants, are actually fairly deeply rooted. So trying to capture the entire root system is difficult.”

Kevin Hultine, Desert Botanical Garden

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