This article first appeared in The Desert Leaf and is part of a series featuring the Sky Islands.
Ornamental grasses from around the world can wreak havoc in the Sonoran Desert. Most dangerous are buffelgrass and fountain grass, which can scorch acres of saguaro cactus if these invasive perennial bunchgrasses catch fire.
A lesser-known grass that towers above them all is giant reed (Arundo donax), also commonly called Spanish cane, carrizo cane, and many other local names. This invasive species resembles bamboo and grows in dense stands that exceed 20 feet in height in areas with perennial water. It poses a major threat to Southwest waterways and is a target of conservation efforts in Tucson’s washes and springs.
A. donax arrived in the U.S. in the early 1800s in Los Angeles from the Mediterranean (it is also native to western Asia).
The reeds were originally imported for erosion management and are now used for ornamental plantings, vegetative screening, woodwind instrument reeds, construction, and even as a biofuel. Unfortunately,
Just north of the Arizona National Golf Club in northeast Tucson, Rock Ledge Spring was covered by an imposing patch of A. donax for decades. Residents recall the giant reed as being one of the spring’s features since the 1960s, but over the 47 years the invasive grew into a multilayered forest of canes growing out of heavy interlocking rhizomes. Prior to a campaign begun in 2024 to remove the giant reed, it was difficult even to know that a spring was buried deep beneath the site — except for the telltale sign of large cottonwood trees at its lower end.
For 18 months, Sky Island Alliance staff and volunteers, including residents from the Sabino Springs and Sabino Estates neighborhoods, hand-cut the long canes and dug up the rhizomes as part of a huge push to free the spring — painstakingly hauling more than 300 tons of plant material from the spring so far. This is the staggering equivalent weight of a fully loaded Boeing 747 aircraft!
As the patch of giant canes was slowly shrunk, water reemerged, and a hidden ciénega was revealed. Rock Ledge Spring is an incredibly rare wet meadow spring — an endangered ecosystem in the Southwest. It’s estimated there are fewer than 200 such sites remaining in Arizona, New Mexico, Texas, and Sonora, Mexico, and nearly half of these are considered dry and no longer flowing today.
After the removal of 300 tons of Arundo donax from Rock Ledge Spring, an endangered ciénega was revived and continues to recover today with the growth of native cottonwoods and other riparian plants.
The revival of Rock Ledge Spring is an inspiring testament to the power of community commitment to the environment. Now that the core infestation of reeds has been removed, the ciénega supports a population of native riparian plants including cottonwood willow saplings, cattails, sedges, and native grasses that emerged from the once-buried soil seedbank. Numerous spadefoot toads occupy the spring; bobcats, javelinas, coyotes, and white-tailed deer frequently visit; and diverse species of birds are making an appearance, including black phoebe, a bird most often seen near flowing rivers.
The transition from a dense stand of A. donax to a recovering ciénega took hundreds of hours of volunteer labor and will continue for years to keep the reed out of this site, serving as a reminder of the importance of early removal of invasive species in all neighborhoods so that native species can thrive.
To learn more about opportunities to help restore desert springs, visit our events calendar.