@Stonekettle They're a slow release of nitrogen that is good for fertilizing, so yes, they'd be good to use with your banana trees.
@Stonekettle @RattusInsanus First few minutes in octodon land so I come to find my favorite blogger. The first post I see he's talking about having a lot of banana trees and coffee grinds. That's a homegrown remedy for diarrhea in certain countries, so naturally, as a medical person, I assume the worst. Kept reading. Glad to find out it's just a random gardening question.
@RattusInsanus That's good to hear. Like I said, I have a lot of both banana trees and coffee grinds. Especially the coffee grinds.