Bananas are constant feeders and it is really better to give less more often. I try to fertilize mine weekly. When I clean out the woodstove, I dump the ashes on them (full of potassium) and we chop up the downed trunks and leaves and leave them in place to rot (and give back nutrients to the plants). We have horrible slugs and snails, some carriers of disease, so I use pellets of BugGetta...works wonders!!!!!