Question: Why doesn’t my bougainvillea flower?

Answer: There are several contributing reasons.  Bougainvilleas bloom best when they are somewhat stunted, so avoid high-nitrogen fertilizers that would promote vigorous new stem and leaf growth.  Keep your plant comparatively rootbound.  Give it full sunlight, and keep it moist at all times.  You will probably see several cycles of blooming over the course of one growing season.