I fertilize all the time on my bananas its mostly what ever organics i can get.i cut dead leaves of my trees and just drop it at the base. Coffee, tea ,mulched leaves egg shell,charcoal from my fire pit,asamite when i can get it,and some 10-10-10 since the yard was almost pure sand when I got this house. As the soil get better i will stop using the 10-10-10.

I don't fertilize after blooming, but I do water a lot. If you don't, you get a hard core in the middle of the bananas.

I usually use the leftover container soil after the tomatoes are done and fertilize one time when I do my other fruit trees right about this time and I like to use slow release fertilizer. At one time in this yard I had 12 different kind of bananas and they all fruited for me, 2 of them were different Namwah, one was better tasting than the other one, now I am down to only one variety, the one that I like the most for various reasons. They get the sprinkle system once a week in winter and twice in summer.

Silvia