Cactus mix is designed to replicate the desert, but Monstera plants come from tropical climes. You can use cactus mix if you absolutely need to, but it will dry out quickly and you’ll need to water the plant more often. To make cactus mix work for Monstera plants, you’ll need to add some peat moss, coco coir, and probably some perlite or orchid bark for drainage. Better yet, mix up your own Monstera mix or purchase one of the products in this list.