Carnegiea gigantea
Family: Cactaceae​
​Common Name: saguaro
​Origin: The saguaro is endemic to the Sonoran Desert, spanning southeastern California, southern Arizona, and northern Mexico. It inhabits desert slopes, flats, and rocky habitats under 4000 feet in elevation.
Description: Carnegiea gigantea is a green columnar cactus with a single trunk, bearing 2-10 stout, upward curving branches covered in large pronounced spines. From early spring to summer, showy, tubular white flowers will form, followed by red fruits.
  • Interesting Features:
    • The saguaro is the largest cactus in the United States, reaching 50-100 feet tall and 6-10 feet wide.
    • The white inflorescence is the state flower of Arizona and only blooms at night, closing again the following afternoon.
  • Uses: The Tohono O’odham people use the saguaro flowers, fruit, seeds, thorns, burls or boots, and ribs for food, shelters, fencing, fiber, trade, and in ceremonies.
    • Other tribes have been documented using Carnegiea gigantea for food, medicine, ceremony, fiber, and trade, including the Western Apache bands, the Hualapai, Yavapai, Maricopa, Pima, Seri, and Yuman-speaking people.

Cultivation and Care:
  • Watering: Low
    • C. gigantea requires very little water, only needing to be watered occasionally during the growing season, and not at all during monsoon season.
  • ​Soil: Plant in sandy, gravely, and well-draining soil with a pH between 6.1 and 7.8.
  • Lighting: Provide full sunlight for the best growth. However, young saguaros should be given partial shade, especially during the summer, to prevent sunburn.
  • Propagation: C. gigantea can be propagated through seed or by softwood, hardwood, and semi-hardwood cuttings.
  • Cold Tolerance: 10°F, USDA hardiness zones 8a to 11.
  • Special Accommodations: The saguaro cannot withstand prolonged temperatures below freezing, and must be protected from intense frost.
    • Additionally, as this species is very slow growing, it may be necessary to buy from a nursery rather than propagating by seed.
    • C. gigantea is protected by law and requires government tags in order to purchase or transport specimens.

Sources:
  1. National Park Service
  2. The University of Arizona Campus Arboretum
  3. Wildflower Plant Database
  4. United States Department of Agriculture
  5. Tucson Cactus and Succulent Society
  6. Dave’s Garden