Quick tip: Roses love bananas… or do they?

Here’s what I was going to write: Don’t toss your banana peels into the Green Bin (or even the compost pile). Instead, chop them up and sprinkle them around your roses, to give the roses a good, organic snack of potassium. I cut mine into bite-sized pieces and apply directly to the soil. The peels soon turn black, as banana peels do, and become invisible.

And here’s the reason I was going to write it: I was taught – and it seems to be the common wisdom – that potassium (along with phosphorus) promotes flowering. However…

When Googling for a link to provide more scientific detail, I came across this article, The Potassium Myth, on Adam Dimech’s website The Story of Flowers. Dimech, with a PhD in Horticultural Science from the University of Melbourne, nixes everything I’ve understood about the relationship of potassium to flowering.

While it is an essential micronutrient [oops, that should be macronutrient] for all vegetative beings (it’s the K in the N-P-K ratio of most balanced fertilizers), according to Dimech, “Potassium has an important role regulating water and nutrient movement in plant cells,” but has nothing to do with flowering.

Live and learn. Still, banana peels are an excellent source of potassium, which is essential for plant health. And when sprinkled around the plants, they lend that nutrient directly to the soil, along with their organic matter. So I’ll probably continue to feed my roses bananas. Besides, sometimes the tales told by those proverbial old wives can confound the logic of science.

9 comments

  1. Hi Helen, I too thought banana peels were good for the roses and could be buried in the hole when they were planted. I know they are good for the compost pile and like to eat my daily quota while perusing the garden then tossing it in to the bin. So tidy! I agree with you about the old wive’s tales too, being an old wife and all. πŸ™‚
    Frances

  2. I’m actually someone that never heard or thought that potassium was for flowers. I think I had a vague idea it was for root health.

    Only thing that was drilled into my head about the fertilizer ratio was that the middle number was for flowers.

    Here’s another tip: Thinking about N-P-K, Nitrogen is obviously the first nutrient, but it’s easy to confuse Phosporous and Potassium. (What does that K mean anyway?) The way I remember which nutrient is which is by thinking of the “ass” in Potassium, which puts it at …the end.

  3. Hi Helen: Interesting post. thanks for sharing. I’ve had good luck with banana peels and roses too. Those old wife’s tales do have their value. Don’t they? Teresa

  4. Teresa and Jan, thanks for your comments. I agree about the sometimes mysterious truths that make up folk wisdom. But, as Dimech says on his site, flowering is a complex process.

    Sarah, I agree that phosphorus is the most important nutrient for flowering. Yet most rose foods have a high 2nd and 3rd number, so that means both P & K. Banana peels have both!

    As to your question, why "K" for potassium (aka potash), here's what I found on Wikipedia:

    "It has the symbol K (Latin: kalium, from Arabic: Ψ§Ω„Ω‚ΩŽΩ„Ω’ΩŠΩŽΩ‡β€Ž al-qalyah β€œplant ashes”, cf. Alkali from the same root)"

  5. Hi Helen! Thanks for this post, it’s very interesting! I never used banana peels for roses. My friend puts them into the tomatoes planting holes. As for me, I put them in a container with water and let them stand for a while, then I use that “tea” for watering any plants, including tomatoes.

  6. Hi Helen. Thank you for your sharing. This is the first time I’ve heard of using banana peels for roses. I will surely give it a try when I grow roses later πŸ™‚

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