The plants are potted (nursery's own pots and soil) and are on a south- facing balcony, where they get sun most of the day. Temperatures range from 70-95 in daytime, depending on season. They are never exposed to frost. They receive a boungainvillea fertilizer weekly, as prescribed, and they get watered at that time only.
What happens invariably is that they start out from the local nursery (outside plants) in full bloom and look great. Then, after the first blooming they get less and less blooms and less and less leaves until finally various arms of the plants die or maintain a subsistence level with few leaves and no blooms.
Over the years, I have tried allowing them to dry out for 2-3 weeks between waterings, have tried west walls and east walls, and each time the results have been similar.
If anybody has some new ideas, I would welcome them, as I love bougainvillea and would enjoy making them thrive on our home's south balcony.