How to prune monstrose apple cactus

Late spring to early summer. Using a sterile serrated knife, make one clean horizontal cut through the column. Dust the exposed flesh with powdered sulfur or cinnamon to reduce rot risk. Leave the wound uncovered in a warm, dry spot until a firm callous forms (1–2 weeks) before resuming irrigation.

Rarely — only for height control or rot removal. Cereus repandus 'Monstrosus' has an irregular, crested growth form that needs no shaping. Pruning is only warranted if a column outgrows its space or shows rot. Cut cleanly through a column in late spring with a sterile serrated blade, allow the wound to callous, and the severed piece can be rooted.

Using a sterile serrated knife, make one clean horizontal cut through the column. Dust the exposed flesh with powdered sulfur or cinnamon to reduce rot risk. Leave the wound uncovered in a warm, dry spot until a firm callous forms (1–2 weeks) before resuming irrigation.