Cactus rotHow to Save a Rotted Cactus. Cacti are generally problem-free plants. Give them a spot of sunlight and a minimal amount of care, and they will grow healthily . Rot. Images: turbinicarpus rot · opuntia rot. Photo: Gregory Whitney rot on cactus plant. Photo: CactusBea rot on cacti plantOct 4, 2002 . The first rule in keeping any cactus or succulent that is not cold hardy,. It's important to get most of the decaying, rotted plant matter away from .