Culture
Thrives in extremely well-drained, gravelly or sandy soils in full sun. Intolerant of frost and wet, cold conditions. Requires very little water once established; overwatering is a common cause of failure in cultivation outside its native habitat. In cultivation, especially outside its native range, it needs protection from frost. Propagation is typically by seed, though it is a slow process. Due to its protected status and difficulty in transplanting mature specimens, it’s best appreciated in its native habitat or obtained from reputable nurseries specializing in desert plants if grown elsewhere.
Noteworthy Characteristics
Carnegiea gigantea, the saguaro, is an iconic, massive, columnar cactus synonymous with the Sonoran Desert. It is one of the largest cacti in the United States. Its slow growth and eventual towering, branched form (in many individuals) make it a majestic presence in its arid landscape. The genus name honors Andrew Carnegie (1835-1919), Scottish-American industrialist and philanthropist who established the Carnegie Institution of Washington which supported early desert botanical research. The specific epithet gigantea refers to its immense size. Saguaros provide food and shelter for a wide variety of desert wildlife, including Gila woodpeckers and gilded flickers which excavate nest cavities in the stems. These cavities are later used by other birds like elf owls.
Problems
Generally pest and disease-free in its native habitat when conditions are appropriate.
Uses
Primarily used as a striking specimen plant in large-scale desert landscapes and xeriscapes within its hardiness range. It’s a keystone species in desert habitat gardens. Due to its massive eventual size, slow growth, and specific cultural requirements, it is not suited for typical residential gardens outside of its native desert environment. Often a protected species, so ensure any plants are ethically and legally sourced.