How to prune sun cup cactus

Spring, when offsets are actively growing. Remove dead or rotten heads by cutting at the base with a clean blade. For offset division, gently detach healthy pups and let all cut surfaces callous for two to three days before potting in dry cactus mix.

Rarely — only to remove dead growth or divide overcrowded clumps. Sun Cup Cactus (Mammillaria microhelia) is a small, globe-forming cactus that needs no pruning. It slowly offsets to form clumps. Only remove individual heads if they rot or die. If the clump grows larger than its pot allows, divide it by separating offsets — that is propagation, not pruning.

Remove dead or rotten heads by cutting at the base with a clean blade. For offset division, gently detach healthy pups and let all cut surfaces callous for two to three days before potting in dry cactus mix.