The rhizome is the part of the underground plant stem that grows sideways instead of upwards. It branches out with each new part developing its own roots and shoots. To propagate a bird-of-paradise, divide the underground rhizome. Choose a shoot with at least three leaves, separate it, and plant it in a pot. Bird-of-paradise doesn’t grow flowers until it reaches a certain size. Don’t worry about this plant getting root-bound in the pot. It won’t bloom unless it is.