Cactus · Sonoran native
Organ Pipe Cactus
Stenocereus thurberi · Cactaceae
Also called: Organpipe Cactus, Pitahaya Dulce, Pitaya
Organ Pipe Cactus (Stenocereus thurberi) is a very low-water cactus native to the Sonoran Desert region well suited to Tucson and the low desert. It thrives in full sun, with a slow to moderate growth rate.
Organ Pipe Cactus at a glance
- Water use
- Very Low (established)
- Sun
- Full sun; tolerates extreme heat and reflected heat.
- Mature size
- 12-20 ft H x 10-15 ft W (multi-stemmed clump branching from the base)
- Growth rate
- Slow to moderate
- Bloom
- White to pale pink, tinged purple/lavender (funnel-shaped, night-blooming flowers opening near stem tips), Late spring into summer (May-July); flowers open at night and close by midday. Sweet red edible fruit (pitaya dulce) ripens in summer.
- Cold hardiness
- Tender; tolerates only brief dips to about 25 F (USDA zones 9b-11). New growth is especially frost-sensitive. In Tucson, plant in warm microclimates with overhead protection.
- Soil
- Well-drained gravelly, rocky, alkaline desert soils; intolerant of wet, poorly drained sites.
- Native range
- Sonoran Desert; in the U.S. limited to far south-central Arizona (notably Organ Pipe Cactus National Monument), extending widely through Sonora and Baja California, Mexico. Native to Arizona but at the cold edge of its range.
- Best used as
- Specimen / vertical accent, Architectural focal point in warm-microclimate xeric gardens, Wildlife and edible-fruit plantings
- Wildlife
- Night flowers pollinated by nectar-feeding bats (lesser long-nosed bat) and hawkmoths; daytime visitors include bees and white-winged doves; fruit eaten by birds, mammals, and harvested traditionally by the Tohono O'odham.
- Toxicity
- Non-toxic; fruit is edible and prized. Spines are a physical hazard.
How to grow Organ Pipe Cactus in Tucson & the low desert
Watering
Drought tolerant once established; deep-water occasionally (about monthly) in the hottest, driest part of summer for faster growth, none in winter. Keep dry during cold weather to reduce frost damage.
Fertilizer & nutrients
Little to none needed; an optional light spring application of low-nitrogen cactus fertilizer during active growth. Do not fertilize in fall/winter.
Pruning & care
No routine pruning; remove only frost-damaged or diseased stems. Cuts can be made at a stem joint with clean tools if necessary.
Notes
Distinguished from saguaro by many slender ribbed stems branching from at or near ground level (organ-pipe form). Frost sensitivity makes siting in a protected, south-facing microclimate important in Tucson. Wild Arizona populations are protected.
Sources: Arizona-Sonora Desert Museum; Organ Pipe Cactus National Monument / NPS; University of Arizona Arboretum / Cooperative Extension; AMWUA Landscape Plants for the Arizona Desert