Why do saguaros only grow in the Sonoran Desert?

Valley 101 show

Summary: When you think of Arizona, what comes to mind? Sprawling deserts or urban sprawl? The Grand Canyon or the mighty White Mountains? Hollywood has painted our state as a wild, uncivilized frontier filled with dangers and adventure. Rugged landscapes split by sharp mountains and dotted with scraggly brush, and the sentinel of the desert. The saguaro cactus. Found only in the Sonoran Desert, the saguaro cactus has a shallow but wide root network – snaking outwards in the hunt for water rather than burrowing deep into the earth. Its roots are often as wide as the cactus is tall creating a firm base to stabilize its towering height. The saguaro's thick, waxy, green skin helps retain water and they hold their breathe all day to make sure they don't lose moisture. They are an Arizona icon and provide essential resources for desert dwellers.   In this week's episode of Valley 101, a podcast from The Arizona Republic and azcentral.com, we venture out into the desert to discover why saguaros only grow in the Sonoran Desert.