Peeling back the truth on bananas

You might have heard: “Don’t waste your banana peels; place them around the base of your tomato and capsicum plants to encourage better flowers and fruit.”

Banana peels are often recommended for improving flowering in roses, too. I’ve also heard the suggestion that they can be placed behind staghorn ferns to improve their health and vigour.

I’m not sure about the origins of this gardening advice, but I’m guessing that it stems from the fact that bananas are rich in potassium and magnesium. They also contain a bunch of other nutrients in small amounts, including phosphorous, calcium, iron and zinc. I have to admit, it sounds like banana peels have magical powers!

The truth is, nothing miraculous happens when you put a few banana peels around your plants. For starters, the scraps from other foods such as potatoes, avocados and melons contain higher amounts of potassium and magnesium than bananas, and they never get a mention.

Despite all this, the nutrients contained in the scraps are not in a form that plants are able to absorb. The scraps need to be completely broken down first. This process takes many months, and you’d need to pile a lot of scraps around the plants to create any impact at all. In the end, all that’s on offer by doing this is a little bit of organic matter. If your plants need nutrients, it’s more reliable to apply fertiliser, compost or well-rotted manure.

It’s the same for staghorn ferns. Placing banana peels behind the plant will add a little organic matter when they eventually break down, but so would a handful of leaves. It’s better to apply a light sprinkle of organic fertiliser if you want to give your staghorns a kick-along.

The best place for banana peels is in the compost or worm bin, along with the rest of your fruit and vegetable waste.

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