California Cactus Barrel

California barrel cactus is a solitary, ribbed desert cactus with a narrow columnar shape and dense protective spines. It grows on rocky slopes in the Mojave and Sonoran deserts, where its form, yellow flowers, and spiny crown make it a distinctive dry-garden specimen ([Arizona-Sonora Desert Museum](https://www.desertmuseum.org/books/nhsd_cactus_.php)). ## Form and season Mature plants are commonly smaller than their maximum, though the Arizona-Sonora Desert Museum reports heights up to about 10 feet. The flowers usually appear near the stem tip in spring; timing can vary by location, and populations near Phoenix may flower in summer. The University of Arizona Campus Arboretum describes plants about 5 feet tall and 1.5 feet across, with yellow to orange-yellow flowers ([profile](https://arboretum.arizona.edu/snyder-preserve-ferocactus-cylindraceus)). ## Placement and water Choose an open, sunny site with sharply draining rocky or sandy soil. The species is adapted to desert conditions and tolerates drought once established. In a container, use a gritty cactus mix and a pot with an unobstructed drainage hole; avoid keeping the roots wet. ## Maintenance Allow room around the cactus for its sharp spines and place it away from narrow paths. Do not move wild plants: native cacti are protected in parts of their range, as the Desert Museum notes. ## San Luis Obispo source The [county plant list](https://www.slocounty.ca.gov/departments/planning-building/forms-documents/environmental-forms-and-documents/plants-information/county-approved-plant-list) rates *Ferocactus acanthodes* F2. [Kew](https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:103619-2) treats this record's *F. cylindraceus* as a synonym of that species' subspecies *acanthodes*. Follow county placement and maintenance guidance.