I am new to this forum, but I just have to share my secrets for the splendor on my open patio. I live in Coral Springs, NW of Ft. Lauderdale, and my secrets (which I researched) are so easy:
Bougainvilla love neglect - I read that you only water them (they get rain showers infrequently here in South Florida) when the leaves are withering. In the Keys, they grow wild and bloom beautifully all year long, and that's the approach to take - no weekly watering & give them plenty of full sun, the more sun, the better.
I also fertilize with Bogain (made just for bougainvilla sold at HD) about once a month, sometimes not that often. I water it in (close to 2 gallons of water), after I've spread the Bogain granules all around the perimeter of the plant, as per the package instructions.
My research also told me that once the blooms fade, you cut them back to the perimeter of the pot (it's hard to do because they look like sticks when you cut them back). They then come back with little green leaves, then more and more lush green leaves, then full blooms.
The only other thing I do is occasionally spray them down with a commercial eco-friendly rose/flower spray also that I buy at HD - not too often, just every now and then. It seems to be a preventative for bugs and fungus to stay away.
All of my neighbors think that I have the best "green thumb" because right now, my patio has 3 bougainvilla in full bloom (incredible splendor) - one is the fushia, another is the purple, and the third is the white with pink infused in the blooms.
They are in big pots with the trellis that it came with from HD, in a good potting soil.
I just had to share; now...maybe when I retire from school teaching in 2 years, I may move on to roses in big pots on my patio. My family, from way back, has always grown many amazing varieties of roses. I'm not ready for the maintenance they require.
For now, I'll stick to my "love to be neglected, love to bloom beautifully" bougainvilla which I have discovered a knack for, here in South Florida. WOW! WOW! WOW!