Founded in agriculture, rooted in life. 

We are engaged in research and teaching in state-of-the-art facilities across the state of Arizonaexploring how plants grow, how they respond to the environment, how they evolve, how they can be bred to support drought tolerance and yield, and how they interact with beneficial and pathogenic fungi, bacteria, viruses, and more.

The University of Arizona School of Plant Sciences (SPLS) is housed within the College of Agriculture, Life and Environmental Sciences (CALES). Through several robust undergraduate, graduate and research programs, SPLS is a leader in the study of plants, the organisms that underpin the survival of all life on Earth and the microbes associated with them.

We take pride in the fact that the School of Plant Sciences collaborates with other schools and departments across our campus to provide the richest possible experience for our students. In addition to our Plant Sciences undergraduate major, we work with the departments of Environmental Science and Biosystems Engineering to offer a major in Sustainable Plant Systems, where students focus on advancing modern agriculture and crop production. We also join with the School of Animal and Comparative Biomedical Sciences and the School of Nutritional Sciences and Wellness to offer a major in Applied Biotechnology, where students learn to develop products and technologies to provide food, fuel, and medicine to serve a growing world population. We also collaborate with the School of Animal and Comparative Biomedical Sciences and the Environmental Science department to offer the undergraduate major in Microbiology, which prepares students to apply systems thinking and find solutions to protect our planet and its inhabitants (including plants) from microbial threats and to improve the reach of beneficial microbes. This well-rounded, multi-faceted education gives students the knowledge and skills they need to launch their careers and improve the community and our world.

Students in plant sciences on UA's main campus, dated May 1914.

Our history

Our roots in plant sciences run deep, extending to the university's founding in 1885. Driven by Arizona’s rapidly growing agricultural economy in the early 19th century, our campus and research plots became an important testing ground for potential commodity crops in the desert Southwest and plant pathology – or the study of plant diseases – became a prominent area of study.

CALES continued to grow and evolve to include horticultural extension and expanded research in controlled environment agriculture, plant breeding and genetics, as well as microbial communities and interactions. We established the first plant molecular biology laboratory in the world in 1960 and led an international team in mapping the genome of rice in 2004. From establishing a 10-acre plot for arid grass experiments in 1889 to using high-tech imaging technology to determine patterns in root architectures in 2024, we work to advance the frontiers of science to improve the human condition.

More than a century after groundbreaking, we remain committed to the ideals of our founding land-grant pillars: to produce employable graduates, to advance purpose-driven science, and to work alongside communities to improve lives and livelihoods. Today we offer four undergraduate degrees and five graduate courses of study, carry more than $8M in research activity annually and serve Arizona's 15 counties and 22 Federally-Recognized Tribes through our Cooperative Extension programs and publications.