Saguaro Cactus

Saguaro is a slow-growing columnar cactus native to the Sonoran Desert. Its ribbed green trunk may remain single or develop upward-curving arms after many decades, making mature plants striking structural features of desert landscapes. White flowers open at night in late spring and early summer, followed by red fruit. ## Growth and habitat The [National Park Service profile](https://home.nps.gov/sagu/learn/nature/saguaro.htm) describes the species’ Sonoran Desert range, sensitivity to freezing temperatures, very slow early growth, and adult heights approaching 50 feet. The [U.S. Forest Service review](https://research.fs.usda.gov/feis/species-reviews/cargig) classifies it in the Cactaceae and notes that mature plants commonly reach about 10 m, with branching and growth varying by site. The [National Park Service profile](https://home.nps.gov/sagu/learn/nature/saguaro.htm) places flowering from late April through early June and describes creamy white flowers. The [U.S. Forest Service review](https://research.fs.usda.gov/feis/species-reviews/cargig) reports mature trunk diameters of about 30–60 cm (12–24 inches), and heights commonly near 10 m with some plants reaching 15 m. ## Siting This cactus belongs in warm, sunny, sharply drained conditions. Natural populations are limited by cold and depend on rainfall and local microsites, so a garden planting outside the Sonoran region needs a sheltered, frost-free position and suitable drainage. ## Maintenance Avoid frequent irrigation and keep water from pooling around the roots. Handle with care because the trunk and arms carry sharp spines. Allow ample space for a mature plant and protect it from freezing weather.