Much like Ken, I have no idea what any of my plumeria want or "need", and I fertilize in the same manor. I start fertilizing in early Spring with a well-balanced, light fertilizer, and fertilize pretty much all the way through late October (when fall begins to start--it varies year to year). Throughout Summer I fertilize with Excalibur (diluted because I use other fertilizers as well), a bloom-booster (for tropicals), and occasionally throw in diluted orchid or succulent fertilizer. There is no method to my madness. I bounce back and forth between super balanced fertilizers and bloom-boosters. I always dilute everything I fertilize with, because I tend to not be able to leave sleeping dogs lie, so I fertilize frequently as it gives me something to do more often. Again, much like ken, all I know is that my plants are frequent and repetitive bloomers, so I just keep doing what I'm doing