How to use banana peel as a fertilizer?

Question

I have heard several times that banana peel can be used as a fertilizer for garden plants (especially so for roses it appears) and verified it with a quick search on the Internet. As it happens, I sit on quite some banana peel right now (well, not literally) from producing jam. There seem to be various ways to use and prepare the peel beforehand:

• cutting it in small pieces and mixing it with the soil surrounding the plants
• charring the banana peel in the oven and spread it afterwards in the garden
• soak the peel in water for a couple of days and water plants with it
• putting it in the compost and use the resulting mix of fruit and vegetable leftovers as usual

What is the advantage of using one form and not the other (if any)? Could you recommend a certain way based on your experience? Is banana peel and the way it is prepared appropriate for all plants equally?

Answer 1

Putting it on the compost gets my vote every time. In the research you did, you probably discovered that banana peels contribute primarily potassium, with only small amounts of nitrogen, phosphorus and magnesium. Because different plants have slightly different requirements regarding levels of different nutrients, most requiring nitrogen in balance with potassium and phosphorus, then that small amount of nitrogen or higher level of potassium may not be appropriate for all plants. If you have a lot of peels, then using them all at once in any of the other ways you suggest would seem to be quite difficult and time consuming, so putting them on a compost heap and allowing the nutrients to contribute to that, in common with other composted materials, then eventually used in the garden, is the most sensible and, in my opinion, valuable option.

You can, though, eat banana peels provided they're organically grown and clean, but they do need a lot chewing, or you can whizz them up in a processor to make a smoothie...

Answer 2

If I see a plant that is fruiting, and could do with a bit of potassium, then I'll take any banana peels that we have, blend it with some water (any stick blender), and then pour it around the roots. I then cover it with a little dirt. Covering it stops flies.

Blending it reduces it to very fine particles increasing the surface area to bacteria, and worms, and so more readily releases the nutrients in a controlled fashion. Composting it would take weeks to months, and would not suit my purposes.