Old Man of the Mountain

Old Man of the Mountain (Oreocereus celsianus) grows best when its natural cycle of strong light, freely draining soil and measured watering is respected. Give it full sun. Water it according to its seasonal needs: moderate in summer; dry in winter. Plant it in very mineral, fast-draining mix. A container with an unobstructed drainage hole is essential, because moisture lingering around cactus roots can quickly lead to rot. Keep its temperature needs in mind: -5 to 30°c. among the most cold-hardy columnars. During active growth, check the compost before watering rather than following a rigid calendar, since heat, light and pot size all change how quickly it dries. Reduce watering during cool or dormant periods, keep the plant well ventilated, and wait until the growing medium is dry before watering again.

From seed; offsets appear late in life. Separate established offsets during the warmer growing season, using clean tools and preserving any roots already attached. Allow damaged surfaces to callus before potting into a dry, mineral-rich mix, then water cautiously while the new root system establishes. Young cacti are especially vulnerable to excess moisture. Use a small pot with excellent drainage, provide bright filtered light while roots establish, and move the new plant gradually into the light, temperature and watering conditions preferred by a mature Old Man of the Mountain.