Monsoon is something many in Southern Arizona look forward to every year—not just because of its impressive storms, but what comes after them.
“It’s pretty glorious. It feels like a second spring,” said Ely Young, a horticulturist with the Arizona-Sonora Desert Museum. “It makes everybody kind of feel alive again after, you know, we’ve been pounded by some heat.”
That’s also true for the plants around us.
In other climates with plenty of rain, seed coats are thinner and allow plants to germinate quickly because conditions are generally favorable for them to grow.
But here in the desert where it’s hot and dry, seed coats are often thicker.
“Because it won’t be getting enough water in the near future,” Young explained. “So during the monsoon season, there is enough water. And often times it’ll wait until several rains before it penetrates through the seed coat.”
During monsoon, that extra rain finally breaks through—and brings an explosion of life.
Tucson Botanical Gardens Horticulture Manager Adam Farrell-Wortman says he can feel his garden “breathe a sigh of relief when the first monsoon rain comes.”
The powerful storms mean extra hours for the staff cleaning up damage and looking for broken tree branches, but also a reason to cut back on water and fertilizer.
“Life just gets easier for a gardener in the monsoon,” Farrell-Wortman said. “It gets easier for the desert.”
Lightning strikes are part of the reason why. They create nitrates which—when mixed with rain— become a sort of “liquid fertilizer."
“The desert would be a very different place if our monsoons didn’t have lightning,” Farrell-Wortman said. “I’m watering all the time in here. But with that nitrogen and other minerals coming down with the rain, all the plants are much perkier and a deeper shade of green.”
Monsoon is the only time of year we see certain plants like the Desert Poppy, the Canyon Morning Glory and the Devil’s Claw.
Others like the ocotillo get a second surge of leaves and flowers.
It’s also time for different ferns and fungi. Last year, a University of Arizona student found a rare purple mushroom on Mount Lemmon—which is believed to be a product of last year’s wet monsoon.
The water and cooler air also bring animals out of the shadows—both after and during rainstorms.
“It just comes alive and it’s absolutely amazing,” said Howard Byrne, zoo curator at the Desert Museum. “Rattlesnakes make drinking bowls out of themselves. Some lizards come out and drink beads of water off the ends of leaves.
“There is about a week and a half or two weeks out of this monsoon season when there are moths that come out that shame butterflies, they are so amazing, colorful and big.”
Burrowed in the ground for most of the year—monsoon means mating season for Colorado River toads.
“Some of these toads have actually lined their chambers with their skin to seal in that moisture, just waiting… Then, thunder,” Byrne explained. “It’s believed that a lot of these animals can actually feel those vibrations underneath the ground and the rain hitting hard. And they’re cued at that point to come out.”
Even if only for a few weeks out of the year, this coming out party is part of what makes monsoon magical.
“It’s during the rain, it’s after the rain,” said Byrne. “And a few weeks of that rain just transforms this whole region, animal and plant-wise, into something that is truly amazing and truly unique, in this lushest desert on planet Earth.”