Giant bird of paradise is a tropical flowering tree that produces exotic angular white blooms in winter through spring, and occasionally into summer in USDA Zones 9 through 11. Known botanically as strelitzia nicolai, it thrives in rich, moist soil, full sun to light shade, and sheltered areas protected from wind. It will reach up to 20 feet in height at maturity and, while it can be grown as an indoor plant, it requires abundant sunlight and several years of maturity to achieve consistent bloom.
Grow your giant bird of paradise in nutrient-rich soil that holds moisture but still drains well and does not remain soaking wet after watering. Position the plant in the soil so that some surface roots are allowed to be exposed.
Water your giant bird of paradise deeply when the top of the soil is dry to the touch. Never allow the lower soil levels to dry out completely, as drought stress inhibits flowering.
Feed your giant bird of paradise four times a year with a slow-release granular fertilizer with a complete balanced formulation. Sprinkle around the roots according to the label directions, applying approximately 1 pound of fertilizer around a large mature clump at each feeding. The smaller and younger the plant is, the less fertilizer to use. Water in deeply and well after application.
Mulch around the roots of the plant once a year with a 2-inch layer of shredded bark, compost or coca bean hulls to hold in moisture, regulate root temperatures and feed the soil.
Allow your plant to become root-bound in its pot or planting bed, as this will encourage flowering. To do so, layer several pounds of compost or rich garden soil over the roots of potted strelitzias each year to compensate for the root crowding and provide soil micro-nutrients to the roots.