Desert plants growing rapidly in the area This is among the largest colonies of prickly pear cactus I've ever seen. In southern Illinois, there is only one species known to occur, Opuntia cespitosa, and it can be found growing Cactus Plants Watering Chart @theplantsheaven Golden Barrel Water: Every 23 Weeks Moon Cactus Water: Every 2 Weeks Old Lady Cactus Water: Every 34 Weeks Elongated Cactus Water: Every 2 Weeks Christmas Cactus Dracaena marginata 'Magenta' der Drachenbaum