Opuntia, commonly called prickly pear or pear cactus,is a genus of flowering plants in the cactus family Cactaceae. Opuntia species are the most cold-tolerant of the lowland cacti, extending into western and southern Canada. hardy to -20 c . these will flower to vivid colours . great addition to your rock garden . locally grown and propagated here in victoria . small $20 med $30 and a couple large $60 . yes plant them outside !! update only small and medium size available now .