Birds of paradise (Strelitzia spp.) bloom seasonally, which means they can bloom at any time of year. Two of the most familiar bird of paradise varieties are orange bird of paradise (Strelitzia reginae), which produces orange and blue flowers, and the white bird of paradise (Strelitzia nicolai), which is named for its white, cream or gray blooms. Also called crane flower, orange bird of paradise grows 3 1/2 to 4 feet tall and 3 to 4 feet wide. White bird of paradise is much larger, growing 20 to 30 feet tall and 6 to 10 feet wide. Both plants grow well in sunny or partially shaded spots and moderately moist soil.
Orange Bird of Paradise
In the right conditions, bird of paradise plants flower three to five years after sowing and one to two years when grown from divisions. Divisions are small pieces of plant that are grown into new plants. A healthy, mature bird of paradise can produce about 36 flower spikes at one time.
Growing outdoors in U.S. Department of Agriculture plant hardiness zones 10 through 12, bird of paradise plants grow and bloom best in organically rich soil and sunny spots that receive at least six hours of direct sun every day. Areas sheltered from winds also help encourage flowering by providing the warmth these plants needs.
Space bird of paradise plants 6 feet or more apart, and spread a 3- to 4-inch layer of aged manure or mature garden compost over the root zone.
Watering bird of paradise plants in winter encourages summer blooms. Though these plants can flower at any time of year, blooms are sometimes more plentiful late spring through summer. Don't water the plants so much the soil becomes soggy, but pay close attention to watering so that the plant never experiences drought.
Water bird of paradise plants when the soil is dry to a depth of 1 inch, applying enough water to moisten the soil to the depth of the root ball.
Slow-release fertilizers supply bird of paradise plants with nutrients throughout the year and help promote flowering. Sprinkle 8-8-8, slow-release fertilizer granules at a rate of 1 tablespoon per 1 square foot beneath the bird of paradise canopy every three months. Gently rake the granules into the soil or mulch to a depth of 1 to 3 inches, and water them well.
White Bird of Paradise
White bird of paradise plants grow in USDA zones 9b through 11, and grow best in freely draining acidic or slightly alkaline soil in areas sheltered from strong winds. In windy spots the leaves become ragged and unattractive.
White bird of paradise plants grown from seed flower in three years in good growing conditions, but flowering can take up to five years. White bird of paradise plants grown from divisions should flower sooner. The flower spikes take several months to mature, and the blooms open over weeks or months. Space white bird of paradise plants 6 to 10 feet apart.
Overwatering harms white bird of paradise. These plants grows best when watered deeply but infrequently, and need little water during winter. Water white bird of paradise when the ground is dry to a depth of 2 to 3 inches during the growing season, and 3 to 4 inches in winter.
A high-phosphate fertilizer helps promote blooming in white bird of paradise plants. Add 1 tablespoon of a 15-30-15 fertilizer to 1 gallon of water, and apply the fertilizer solution to the plant once a week while it's actively growing. Stop feeding white bird of paradise when growth slows down or in fall. Overfeeding encourages green, leafy growth but few flowers.