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April 20, 2022

Community is asked to get involved and help count these desert icons

Phoenix, April 20, 2022, Desert Botanical Garden (the Garden) is conducting a census of saguaro cactus growing in metro Phoenix to better understand the health and adaptation of the Valley’s population. The Garden is enlisting the help of local residents to provide information, pictures and a count of the number of saguaros throughout the Valley.

Starting in May, the community can help the Garden document saguaros (Carnegiea gigantea) in their neighborhoods through iNaturalist, a free smartphone app and website. Participants can share their observations on the app under the Metro Phoenix Saguaro Census project. An observation can include photos, a location and notes about the general health of the saguaro.

The summer of 2020 was historically one of the hottest and driest summers for the Valley. That summer the Phoenix area lost numerous saguaros. There were many reports online from residents whose cactus lost an arm or fell over. The cause is unclear. To look for answers, the Saguaro Census will count and document saguaros in metro Phoenix. This is the first step to generate a database to monitor the saguaro population in the Valley, learn more about their health and research the effects climate change might have on them.

“Urban areas are heat islands. Plants growing in cities are under serious heat stress — several degrees higher than in the wild. If saguaros in the city are dying now, do we expect this to happen to wild saguaros under future climate change? We can start planting saguaros brought from drier and hotter regions to better adapt our urban saguaro population to withstand future climatic conditions,” says Dr. Tania Hernandez, the Garden’s New World Succulents Specialist.

The Saguaro Census is part of a larger project led by Dr. Hernandez. The project seeks to understand the biology, distribution and genetics of the urban saguaro population by comparing them with their relatives growing in the wild. The project will also be used to develop tools to understand and preserve endangered cactus species in the Southwest with substantial community involvement.

The Saguaro Census is in collaboration with the Metro Phoenix EcoFlora and the Save Our Saguaros project, led by Girl Scout Gold Award recipient Ella Werre.

“People from the Phoenix area care so much about saguaros because they are part of our identity as Arizonans. I’m really excited to work on this project to make real change happen. I did my Girl Scout project in the hopes that the data I was collecting could be utilized by real scientists to help saguaros in the Phoenix area. Small steps, like using your smartphone to document saguaros in your area on iNaturalist, can lead to big changes in the quest for answers on saguaro health,” says Were.

“This is a great opportunity to study plant responses to heat and stress. Saguaro plants in the city are a climate change experiment, which would be impossible to generate artificially. With information from the census, we will select some plants to perform further studies, analyze how they are adapting at the genetic level, and monitor their physiological responses over time, particularly in the hot summers,” says Dr. Hernandez.

For more details about the Saguaro Census and how you can get involved visit
Join the Saguaro Census project and view the training video here to become more familiar with iNaturalist.

About Desert Botanical Garden
An Arizona icon for more than 80 years, Desert Botanical Garden is a living museum of more than 50,000 plants. Founded in 1939, the Garden is a premier institution focused on education, exhibition, research and conservation of desert plants of the world, with an emphasis on the Sonoran Desert. A Phoenix Point of Pride, the Garden’s 140-acre site is distinguished by its robust collection of cactus and agave plants, as well as its scope and excellence of its programs in education, horticulture, plant research and conservation. Learn more at

About Metro Phoenix EcoFlora
The Metro Phoenix EcoFlora is a collaborative community science project of Desert Botanical Garden and the Central Arizona Conservation Alliance (CAZCA). The focus of the project is to increase understanding of biodiversity and urbanization, make plant science meaningful and open for everyone, and contribute to local conservation efforts. The project is addressing urban biodiversity challenges by creating opportunities to observe and learn about nature and urban ecosystems and to be engaged in scientific collaboration and plant conservation efforts.

About Dr. Tania Hernandez
Tania Hernandez is a Desert Botanical Garden research scientist specializing in succulent plants, particularly agave and cactus. The work in her lab is motivated by an interest to understand how and when these plants originated and how they evolved their adaptations to withstand water scarcity. Born and raised in central Mexico, Dr. Hernandez has been surrounded and astonished by cactus diversity all her life. What she finds more interesting is how these plants are modified from a common plan seen in most other plants, and then diversified into hundreds of species. The magnitude of these modifications has no equal in any other living lineage. Under her recent appointment at the Garden, Dr. Hernandez is working on developing genomics tools applied to better understand and preserve agave and cactus biodiversity.

About Save Our Saguaros: A Girl Scout Gold Award Project
Ella Were has been a Girl Scout for 12 years. As a culmination of the time and passion she has put into the program, she strove to complete her Gold Award, a service-based award that is the highest level of achievement in Girl Scouts. For her project, she was inspired by the death of a saguaro in her front yard, an event that surprised her, as it had seemingly been in good health. Working with Jeny Davis, EcoFlora Coordinator at Desert Botanical Garden as her project mentor, she put together a brochure and a website in hopes of helping the public understand more about this iconic symbol of Arizona. Using iNaturalist, she created a place where people can document saguaros in the urban Phoenix area to provide scientists with a more accurate look at population and general saguaro health in metro Phoenix.