Social media is full of claims that soaking banana skins in water creates a fertiliser capable of producing bigger leaves and better blooms. The idea is appealing: bananas contain potassium and small amounts of other nutrients, so why not put the peel to work?
The method usually involves placing banana peels in a jar of water, leaving them to steep, and then pouring the liquid onto houseplants. However, as gardeners have pointed out, there is no way of knowing the strength of the mixture or which essential nutrients it might lack.
In a practical test, one peace lily was fed with banana peel water while another received a standard fertiliser. The plant given the banana water showed no visible difference, but its soil developed a slimy layer and attracted a small cloud of fruit flies.
The conclusion is that houseplants require a balanced diet rather than a random splash of whatever has been steeping on the kitchen counter. Rotting peel can also bring unpleasant smells and slime to your pots.
If you are determined to try the trick, it is best to steep a fresh peel for no longer than a day, strain it well, and dilute again before use. Even then, it is advisable to keep it away from houseplants and apply it only to outdoor beds or borders.
