I have a bougainvillea that I have nursed along for several years and have had success, but not this year. I have tried at regular feeding intervals Ironite, Miracle Gro, and last week, molassis. I live in Southeast Texas, about 50 miles from Houston. What else can be done, or just give it up and discard? Any help would be appreciated.
This does appear to be either a nutrient issue.
Since you have tried a few different things, I might suggest Epsom Salt.
Here is a link to refresh you on the care requirements.