Bird’s nest ferns (Asplenium nidus) are naturally epiphytic, meaning they grow on the surface of other plants. In their rainforest homes, they can be found growing high in the crooks of trees. They form a series of erect, spoon-shaped, bright green fronds that rise from a central rosette. Healthy plants can have fronds up to 5 feet long, but bird’s nest ferns grown as houseplants typically have fronds that grow only about 2 feet long. The plants have a moderate growth rate. They’re best planted in the spring, though houseplants generally can be started year-round.