Your plant may not be mature enough to produce flowers. Young plants usually do not bloom for a few years after they are planted. Well established crowded clumps produce the most flowers. Large clumps can be divided during warm weather, but the divisions may not bloom for several years and flower production will initially be light.
The bird-of-paradise will grow in full sun to partial shade, but plants in full sun produce more flowers. Fertilize plants in spring and summer but not in fall and winter. If you want small plants to grow rapidly use a fertilizer with more nitrogen than phosphorous. To obtain more flowers on established plants use a fertilizer with as much, or more, phosphorous than nitrogen. Water plants thoroughly when you irrigate, then wait until the soil is somewhat dry before you irrigate again.
When flowers are removed pull them from the plant if you can instead of cutting the stem. This keeps the base of the flower stem from crowding the lower part of the clump. Grasp the stem firmly below the flower head and pull up and outward. Do not pull flowers from young plants until they are several years old and have developed a good root system that will withstand a strong tug.
By V. Lazaneo, Urban Horticulture Advisor, Emeritus, UC Cooperative Extension, October 2012