Certified GKH Gardening Expert
The colored cactus are grafted to a green cactus, usually the dragonfruit, to survive. Those little babies on top will not survive on their own without being grafted to one of the three suitable host cacti. Most people use dragonfruit, or hylocereus, as the green cactus. Since the babies on top do not make chlorophyll, they cannot survive without a cactus that can. These do not occur in nature.