Bird of paradise (Strelitzia reginae) produces fans of deep green leaves and orange-red flowers that resemble a bird taking flight. These tropical plants grow in U.S. Department of Agriculture plant hardiness zones 10 to 12, but they also thrive as houseplants in a well-lit room. You can propagate a bird of paradise by dividing and separating its thick, tuberous underground stems, or rhizomes, into multiple new plants.
Early spring, just before the first flush of new growth appears, is the best time to divide a bird of paradise. Potted indoor plants may begin putting on new growth earlier, depending on indoor temperatures and plant health, so you may need to divide in late winter. If you notice new, tender stem tips emerging, it's time to divide. The plants benefit from division every three years, or when they begin to outgrow their pot if you grow them in containers.
Digging up the tuberous roots without causing damage is key to healthy propagation. You can simply slide potted plants from their container and gently brush or shake the excess soil from the rhizomes. For garden plants, dig around the plant starting 10 inches from the base to minimize the chances of cutting into a root. Slide your shovel beneath the root mass and lift the entire plant from the ground.
The bird of paradise rhizomes look like swollen horizontal tubers with roots and fans of leaves attached. Disinfect a sharp knife in a solution of 1 part bleach to 9 parts water before dividing to prevent disease problems. Cut the rhizome into 3- to 4-inch sections. Each section should be at least three inches long and contain a full fan of leaves, otherwise it won't regrow after planting. Trim off any damaged sections and dispose of them, disinfecting the knife again after making the cut.
You can replant the rhizome sections back into the garden bed immediately after dividing. Plant in a well-drained but moist garden bed that receives full sunlight, spacing them 4 feet apart and setting the sections at the same depth they were growing at before. Alternatively, plant the rhizomes in small pots with bottom drainage holes, using a potting soil formulated for tropical plants. Keep the soil moist and provide all-day sun. You can then transplant the established plants outdoors or into a large permanent pot after eight weeks.
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