If the canna orchid fails to bloom, there are usually a number of environmental factors that contribute to the problem. From temperature to moisture, all of the growing conditions of the canna orchid must be met adequately for the plant to produce blooms. Keeping canna orchids healthy encourages better success with blooming.
Canna orchids require a great deal of both sunlight and water to bloom. A lack of water or too much shade weakens the plant, slowing its growth and preventing it from blooming. Additionally, orchids are tropical plants and require warm temperatures to bloom and grow. Keeping the canna in an area where temperatures are low will put the plant in a dormant state or kill it, and it will be incapable of producing flowers.
Canna orchids also refuse to bloom if they are planted too deep in the soil. A lack of oxygen in the soil will starve the plant of air, weakening it and making it susceptible to pests and diseases. Ensure that the roots of the canna are covered, but that the stem of the plant is not buried too deep in potting material or soil. Use soil designed for the growth of canna orchids to provide the plant with the right nutrients.
Canna orchids need space in which to grow. If their root systems are crowded by the presence of other plants, the orchids will not bloom because they are forced to compete with other plants for resources and water. Leave at least a foot of space between cannas and other orchids or plants, or grow canna orchids in their own containers, to encourage healthy blooming.
Canna orchids require annual pruning to grow each year. After the first frosts appear in the fall and kill off the current season's growth, prune the canna orchid back so that it is roughly 6 inches tall. This helps remove dead growth that can house harmful pests and encourages new, healthy growth to emerge in the spring. Pruned canna orchids will produce blooms, while cannas that are not pruned may be unable to do so.