IDK the science, but it's one of those gramma'isms that really works. She said she did it for roses, and I've tried it on many different kinds of plants over the yrs, when they "should" be blooming but are not.
If outside, I just put a whole banana, or just the peel (doesn't seem to matter which) on the soil near the base of the plant. For indoor plants, banana can be pureรฉd, diluted in water & used to water the plant.
