How to prune oreocereus trollii

Spring or early summer, only when damage is present. Use a sharp, sterilised knife to cut cleanly below any dead or rotted section. Dust the cut surface with powdered sulphur or cinnamon and allow it to callous for several days before watering.

Rarely — only when dead or damaged tissue appears. Oreocereus trollii (Old Man of the Andes) is a columnar cactus that needs no pruning. Simply remove any dead, shrivelled, or frost-damaged tissue with a clean, sharp blade. Beyond that, leave it alone — cutting into healthy green tissue serves no purpose and opens the plant to rot.

Use a sharp, sterilised knife to cut cleanly below any dead or rotted section. Dust the cut surface with powdered sulphur or cinnamon and allow it to callous for several days before watering.