The optimal time for transplanting is at the beginning of active growth, which for most tropical houseplants is in spring. The exception to this are winter-blooming houseplants such as Jasmine and Amaryllis that are best potted in the fall after their dormant period. Some houseplants just like to grow potbound and resent being moved altogether. Rather than repotting plants such as Clivia and Fern, let them remain in a maximum size pot and topdress annually with a sterilized houseplant potting soil.

Courtesy of the NYBG Plant Information Service