Oreocereus celsianus
Light: Full sun to light shade; in Phoenix, provide afternoon shade and avoid intense reflected heat. Acclimate gradually to direct sun.
Water: Low water; water deeply but infrequently during active growth, allowing soil to dry completely between waterings. Keep nearly dry in winter; do not increase watering simply because temperatures rise.
Soil: Extremely well-drained, gritty soil with a high mineral content. Use raised planting areas or containers with drainage holes where native soil drains poorly.
Mature size: Typically 6–10 feet tall, potentially reaching 12 feet; branching clumps may spread 3–6 feet wide over many years.
Bloom: Mature plants may bloom in late spring to summer; flowering can take many years and is uncommon on small container plants.
Evergreen / deciduous: Evergreen.
Growth rate: Slow.