How to Use Bananas as Fertilizer. Bananas are rich in both phosphorus and potassium which are important macro-nutrients plants need. Rose bushes in particular benefit from added potassium; however, all potassium fertilizers are extremely expensive. Banana peels are a natural source of the phosphorus and potassium found in expensive fertilizers, but why buy when making your own banana fertilizer is as easy as tossing the skins?
Add banana peels regularly to your compost bin, if you happen to have one. The high levels of phosphorus and potassium are an essential addition to your homemade fertilizer. Whole banana peels break down fairly rapidly; however for faster decomposition, cut the peels into small pieces.
Cut a banana peel into small pieces and mix them up with fresh soil for an added boost when planting a new plant. Banana peels can be mixed into the soil around plants, shrubs and trees at any time for an added fertilizer. If you happen to have access to a banana tree, add leaves, stalks and skins to your soil as well.
Toss a banana peel onto the ground around your shrubs, flowers or in your garden as an extra fertilizer every time you enjoy a banana. The peels disintegrate and are absorbed into the ground quickly.
Use small pieces of banana peels to add fertilizer to your garden mulch. When cleaning up the yard in the spring and summer, adding a boost of potassium and phosphorus rich banana peels can help your plants grow and flower better than ever.