Of course, you can just add these to the compost too. We eat a LOT of bananas in this house – a LOT – so we have plenty of skins. I put these on a tray in the bottom of the oven, allowing them to air dry until I bake something, then heat dry for the rest. Then I grind them in a coffee grinder, with any (washed, dry) egg shells and last year’s red clover harvest (as it turned out, I didn’t like it as tea!). Store the mixture in an old antibacterial wipes container, sprinkling a good handful in the hole before planting out plants, or mixing through my own compost to boost it. I’ve also occasionally dissolved a spoonful in the watering can to give the plants a kick!