Bird of paradise plants (Strelitzia reginae) grow about 5 feet tall and wide and bloom in spring and summer, producing flamboyant orange and blue flowers. For best results, split or divide them after they have been blooming for a few years. It's also possible to start new plants by digging up and replanting newly formed suckers that have developed two to three leaves.
When to Divide
Bird of paradise plants grow outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 12 but they grow as houseplants everywhere. Divide outdoor and indoor bird of paradise plants in early spring or late summer before they begin to put on new growth. Water the plant generously a day or two before dividing.
Select a new planting site for the bird of paradise divisions before digging the plant up. Plant the divisions in full sun for profuse flowers. They will grow in shadier areas but will bloom less. Tolerant to a variety of soils, bird of paradise plants perform best grown in fertile, well-drained soil.
Dividing Outdoor Bird of Paradise
Things You'll Need
Mix a 2- to 3-inch layer of aged cow manure or compost into the soil in the new planting site to a depth of 10 to 12 inches one to two weeks before dividing the plant. The soil should be acidic with a pH of 6.8 or lower. Mix 2 1/2 pounds of sphagnum peat moss per square yard into the soil to lower the pH by 1.0, or from 7.5 to 6.5, if the soil is not already acidic.
Push a dirt shovel all the way into the soil 6 inches away from the base of the bird of paradise's stems all the way around the plant. Push the shovel in again, 6 inches away from the stems, and lever the clump up out of the soil with the tip of the shovel. Very large plants can be cut into more manageable sections. Push a sharp spade straight down through the center of the plant to split it into two or four sections.
Rinse the dirt off the roots with a garden hose or gently shake it off. Use a sharp, sterilized knife to cut the rhizomes into sections. Rhizomes are underground stems that the roots grow from. Sterilized the knife with ordinary household disinfectant and rinse it off before using the knife to prevent damage to the plant tissue. Each division must have at least 3 inches of rhizome with roots and one or two leaves.
Plant the divisions right away. Do not let them dry out while waiting to be planted. Plant them at the same depth they were growing previously and firm the soil around them to remove air pockets. Water them generously after planting. Keep the soil lightly moist for a few months after planting the divisions.
Dividing Indoor Bird of Paradise
Things You'll Need
Houseplant potting soil
Fill new plant pots with fast-draining houseplant potting soil. Either peat-based or soil-based potting soil is fine. Use plant pots that have drainage holes. The pots should be large enough to hold 1 to 2 inches of soil all the way around the rhizome and root mass of the new division.
Remove the bird of paradise plant from its container. Rinse off or gently shake the soil off the rhizomes. Cut the rhizomes into sections with a sharp knife that has been sterilized with household disinfectant and rinsed. Each section must be at least 3 inches long with roots and at least one or two leaves.
Pot the division in the prepared container, firming the soil around the rhizomes. Plant the division no deeper than it was originally growing inside the container.
Water the divisions generously after potting them up. Put them in an area where they will get bright, indirect light for two months while they recover. Keep the potting soil slightly moist and do not give them any fertilizer during the recovery time. After plants have recovered and start establishing themselves inside the new container, move to a location with bright sunlight.
Wait until the bird of paradise has outgrown its container and the container is cracked before repotting. The plant blooms best when pot-bound.
Repotted bird of paradise plants should bloom in approximately two to three years.