AZ Arboretums

Carnegiea gigantea

giant saguaro

Common: Giant saguaro
Family: Cactaceae
Origin: Northern Mexico, Arizona, California
Sunset zones: 12, 13, 18-21
Light: Part shade to full sun, except when seedlings
Soil: Well drained soil; prefers rocky or loose soil
Growth: Main trunk of mature saguaro may be 40 ft. high and 2 ft. in diameter.
Temperature: Damaged by long hard freezes in 20F
Water: Water newly planted cacti very little; roots are subject to rot before they begin active growth. Reduce watering in fall to allow plants to go dormant.

Columnar and branching, with prominent ribs that gives it a fluted appearance. Grows very slowly to 60 ft. or more. When 60-75 years old and about 20 ft. tall, they may sprout budding branches or arms.

Slow growing; stays pot size or garden size for many years.

Makes focal point. Verical form, desert effect.

Mature plant blooms in May. Night blooming.

Oval, edible fruit splits open to show red pulp that is sometimes mistaken for flowers. White, single flowers 4-5 in. long, appear in wreaths in late spring or early summer (State Flower of Arizona).

Heavily protected by law, require tags from US Commission of Agriculture for legal purchase or transplant. Protect seedlings from direct sun, which will cause burned spots on the cactus.