Arizona’s saguaro cacti, a symbol of the U.S. West, are leaning, losing arms and in some cases falling over as record-breaking extreme heat consumes the state, Reuters has reported.
Summer monsoon rains the cacti rely on have yet to come, testing the desert plants’ ability to survive in the wild as well as in cities after temperatures soared above 110 degrees Fahrenheit for 25 days in Phoenix, Tania Hernandez, a succulents cactus scientist at Phoenix’s Desert Botanical Garden, told Reuters. Phoenix’s Desert Botanical Garden, which covers an area of 140 acres, has over 2/3 of all cactus species, including saguaros which can grow to over 40 feet tall.
“These plants are adapted to this heat, but at some point, the heat needs to cool down and the water needs to come,” said Hernandez.
Plant physiologists at the Phoenix garden are studying how much heat cacti can take. Until recently, it was assumed that the plants could adapt to high temperatures and sustain themselves in a drought. However, Arizona’s heat wave is testing those assumptions.
More:All the records Arizona’s heat has broken this month; this week’s forecast
‘Sentinel of the Southwest’, cacti need to cool down at night or through rain and mist. Long periods of high temperature can weaken and eventually kill saguaros by damaging them internally.
According to the National Park Service (NPS), the average life span of a saguaro is 150–175 years, though some plants may live more than 200 years.
Cacti in Phoenix are being studied as the city is a heat island, mimicking the higher temperatures that plants in the wild are expected to face with future climate change, Hernandez told Reuters.
Caring for saguaros
If you have a saguaro in your yard, the Desert Botanical Garden recommends giving them supplemental water during periods of drought to ensure that they survive the hot summers.
“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 4-6 hours. This will allow the water to reach deep into the soil (2-3 feet) where the bulk of the roots are,” the garden’s experts recommend. Doing this process once a month during peak summer will be enough to help the plant stay hydrated until it rains, the center says.
However, it warns against overwatering because if water is left sitting around the base of the cactus, it can cause it to fall down.
Heat in the Southwest
This week was the Southwest’s third week of record-breaking heat.
In Arizona, the Phoenix Metropolitan Area has seen temperatures topping 110 degrees daily with Tuesday hitting 118 degrees. The National Weather Service continues to issue excessive heat warnings in the area, advising people to stay indoors and avoid the outdoors as much as possible.