Cereus repandus f. monstrosus
Light: Full sun to light shade; in Phoenix, provide afternoon shade from intense summer sun, especially for young or recently planted specimens. Acclimate gradually to direct sun.
Water: Low water once established. Water deeply, then let soil dry thoroughly; irrigate occasionally during prolonged summer heat. Keep nearly dry during cool winter weather.
Soil: Very well-drained, sandy or gravelly soil. Use a gritty cactus mix in containers and avoid low spots where water collects.
Mature size: Typically 10–15 feet tall and 6–10 feet wide in landscapes; older specimens may grow larger. Size varies with the particular monstrose form and growing conditions.
Bloom: Mature plants may bloom sporadically from late spring through summer; flowering is less reliable than in the normal columnar form.
Evergreen / deciduous: Evergreen; photosynthesis occurs in its fleshy green stems rather than leaves.
Growth rate: Slow to moderate; generally slower than the normal columnar form.