I don't have a clue but love the picture. You might want to try the Florida forum where more people can grow bouganvillas. They don't usually winter over here.

how long do you water 2x a week, also do you have a sprinkler system. they look very vigorous which means they are getting probably too much of something
also, some kinds have to be older to bloom better
just remember, where they bloom the best, in the Key's, they get NOTHING.
you might want to try this: buy bloom fertilizer, mix as per direction and spray the leaves, but don't do it in the middle of the day. i did that with my bleeding heart and it helped to produce blooms.

Bougies will bloom better with less water and even less fertilizer. The more neglected, the better.

Manny E Just wait for the fall. They'll be beautiful.