As far back as I can remember, the tip has been circulating that you can “feed” your roses by placing or burying banana peels at their base.
According to this tip, banana skins are rich in in potassium and therefore, as they decompose, they’ll stimulate the rose bush to grow and bloom better. And guess what? That is true… but only just barely.
Yes, banana peel contains potassium: about 78 mg/g. And it also contains other minerals – calcium (19 mg/g), sodium (24 mg/g), manganese (76 mg/g) and iron (0, 6 mg/g) – that roses also need to grow well. In fact, not just roses, but any plant. So there is no reason to reserve your banana peels strictly for rose bushes rather than to share them with anything else you may be growing. That’s the first bit of misinformation.
The second is that there is something extra special about banana peels as fertilizer, but in fact almost all table scraps and garden waste also contain potassium plus often something roses will appreciate even more: nitrogen and phosphorus. So logically it would also be interesting for your rose bushes if you placed wilted lettuce, potato skins, weed leaves or xx (insert here the waste product of your choice!) at their base… but then your rose garden would start to look more like a garbage heap than a flower garden.
If you decide to do so start dumping kitchen scraps or garden waste around your rose bushes, it would be wise to either bury the waste or to cover it with mulch. When waste is composted directly in the garden, it’s called pit composting if you big a hole or trench and bury it or sheet composting if you spread it around and cover it with mulch.
Mix Your Ingredients For Quality Compost
Rather then drop banana peels at the base of roses, I suggest you instead put them in your compost bin along with all the other materials you recycle and then that you share the compost thus produced with all your plants. Compost produced by a composting a variety of products will be more balanced than banana peels alone and therefore more beneficial for plants, including roses.
Banana Peels In Winter
If your composter is not accessible in the winter, just freeze your banana peels in the meantime. Yes, in the freezer or outdoors (many people simply leave in a container for that purpose near the back door during freezing weather). Interestingly, banana peels decompose more rapidly after they’ve been frozen and thawed out than if you apply them fresh.