Cacti feel the burn of harsh Phoenix summer

Posted: Updated:
Tracey Rhodes, a horticulturist at Phoenix Desert Botanical Gardens, spreads a net over a yellowing whale’s tongue cactus.(Source: Chris Benincaso/Cronkite News) Tracey Rhodes, a horticulturist at Phoenix Desert Botanical Gardens, spreads a net over a yellowing whale’s tongue cactus.(Source: Chris Benincaso/Cronkite News)
Even native species like prickly pear cactus rot and die under record breaking summer temperatures, McMahon said. (Source: Chris Benincaso/Cronkite News) Even native species like prickly pear cactus rot and die under record breaking summer temperatures, McMahon said. (Source: Chris Benincaso/Cronkite News)
Cactuses are covered with black nets to protect them from tissue damage because of the blazing summer sun, McMahon said. (Source: Chris Benincaso/Cronkite News) Cactuses are covered with black nets to protect them from tissue damage because of the blazing summer sun, McMahon said. (Source: Chris Benincaso/Cronkite News)
Certain cactus species can whither under the Phoenix sun, said arborist Scott McMahon, who has taken care of cacti at Desert Botanical Gardens since 2001. (Source: Chris Benincaso/Cronkite News) Certain cactus species can whither under the Phoenix sun, said arborist Scott McMahon, who has taken care of cacti at Desert Botanical Gardens since 2001. (Source: Chris Benincaso/Cronkite News)

By CHRIS BENINCASO
Cronkite News

Even a cactus has limits.

The Arizona icon of desert survival can’t always take the heat. Record-breaking temperatures that draw shudders and international attention also have been rough on many types of succulents.

“Certain deserts are so harsh that even cacti won’t live in them,” arborist Scott McMahon said, who has overseen the cacti at Desert Botanical Gardens in Phoenix since 2001.

Workers cover vulnerable species with black nets to protect them from the sun, especially if they’re not native to the Sonoran Desert. But even native Phoenix species have encountered more trouble with each passing summer, he said.

“If the heat is too severe they will stop growing,” he said. Cacti require temperatures of about 85 degrees at night so they’re able to respire, the plant equivalent of breathing.

[SPECIAL SECTION: Extreme Heat]

If nighttime temperatures remain too high the plants’ water reserves will slowly be depleted.

“They’ll essentially cook,” McMahon said. “They’ll just sort of stew in their own juices, and after several weeks of this they will die.”

Direct sunlight also threatens succulents’ health.

“When this gets too intense it’ll burn the tissue and actually kill it,” McMahon said.

One cactus species remains scrappy under the Arizona sun.

Saguaros, cactus royalty, store water so efficiently they can endure what other cacti can’t handle.

Click/tap here to download the free azfamily mobile app.

Copyright 2017 KPHO/KTVK (KPHO Broadcasting Corporation). All rights reserved.