Carnegiea gigantea
saguaro
Sonoran Desert (southwestern North America)
Overview
Carnegiea gigantea, the saguaro, is a giant columnar cactus that grows as a tree-like succulent 15-50 feet (4.5-15 m) tall, with a thick, fluted, ribbed green trunk 18-30 inches (45-75 cm) in diameter. Mature plants develop several upward-curving arms, though some remain unbranched, and a full-grown specimen can weigh several tons when full of stored water. The ribs bear clusters of stiff grey spines up to 2 inches (5 cm) long, and the pleated surface expands and contracts as the plant takes up and uses water. In late spring waxy white flowers about 3 inches (8 cm) across open near the stem tips, each lasting under a day and opening at night into the morning. They are followed by red, fleshy fruit holding thousands of tiny black seeds, long harvested by Indigenous peoples of the Sonoran Desert. Growth is slow, often under 1.5 inches (4 cm) a year when young, and plants may take 50-75 years to grow their first arm. Individuals can live 150-200 years. It depends on the nurse-plant shade and rare rains of its native desert range.
Native Range
Native to the Sonoran Desert of southern Arizona, southeastern California, and the Mexican state of Sonora. It grows on rocky slopes, bajadas, and desert flats, typically below 4,000 feet (1,200 m). Young plants establish in the shade of nurse trees such as palo verde and mesquite.Suggested Uses
Used as a specimen in desert and xeriscape landscapes within its climate range, given wide spacing and full sun. It serves as a nesting site for desert birds such as Gila woodpeckers and elf owls. Outside arid regions it is grown only as a container or conservatory plant while small.How to Identify
Appearance
Size & Dimensions
Height15' - 50'
Width/Spread1' - 10'
Reaches mature size in approximately 75 years
Bloom Information
Flowers from late April into June, with peak bloom in May. Each waxy white flower opens at night and closes by the following afternoon, lasting less than a day. Bats at night and bees and white-winged doves by day pollinate the flowers, which then form red fruit ripening in June and July.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 8-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows only in hot, frost-free desert conditions with full sun, sharp drainage, and infrequent deep rain. It stores water in its pleated stem and tolerates long drought, but standing water and prolonged frost cause rot and tissue damage. It grows extremely slowly and resents transplanting once large. In its range it is protected by law, and removal or harm to wild plants is restricted. Outside arid climates it survives only under cover with careful, sparing watering. Seedlings need the shelter of a nurse plant or shade to establish.Pruning
No pruning is needed or usual. Damaged or rotting tissue is sometimes cut out to stop decay from spreading. Arms broken by frost or storms do not regrow in the original form.Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons