The exciting name for these plants refers to the lump of volcanic rock on which they are mounted. Anthuriums (Wax Flower), ferns, bromeliads, and more can be grown on this porous rock that feeds water to the plant roots which are adhered to the rock. This makes the decision of when to
water super easy—just keep water in the saucer in which the plant is sitting, and the rock will soak the water up just like a sponge. Occasionally use a little fertilizer water to keep the plant green and growing.
The plants that do well when grown in this manner are Epiphytes, that is, plants which grow up on trees and rocky hillsides in their natural habitats. Their roots are adapted to being exposed to the air, rather than buried in the soil, and so they are happy as long as sufficient water is provided.