Hmmm, I have never heard of doing that but I would have to question why anyone would do it. Passiflora are very aggressive climbers, they wind those tendrils around anything and everything, I would think that it would choke the banana. I have to keep all my passies away from all the other plants.
Sorry it does not answer your question.

Sorry for the confusion, I don't mean a banana plant, I mean a piece of fruit buried under the soil. As it decomposes a significant amount of potassium is made available to the passiflora roots. I do bury a whole egg in with my container grown tomatoes.
Karyn

I do it all the time. It would probably be better to just bury the peel, as the fruit can attract ants. The peel also dries out fairly quickly when exposed to the sun, making it less of an insect attractant.

Thanks Baci. I think I'll try the peel. I was worried about attracting ants and fruit flies. How far down in the soil do you bury the peel?
Karyn

I chopped up some banana peels and dug them down a few inches into some of my plants. I'll see if it makes a difference.
Karyn