Friday, July 17, 2015

Twining direction in beans: true story or myth?

In other words, I'm so confused. :)

I've read over and over that runner beans (Phaseolus coccineus) twine clockwise, while most other climbing beans, in particular Phaseolus vulgaris, twine counter-clockwise. So I thought I'd do a post on that, and started taking photos of the beans at the Derwood Demo Garden. I'm sorry for the poor quality of the photos, but you can see the twining stems pretty well.

This is a Romano bean, Phaseolus vulgaris. And for another P. vulgaris, an old photo of Borlotto beans I took several years ago:

Here are climbing lima beans, P. lunatus:

And just for a bonus, hyacinth beans from a totally different part of the world, Lablab purpureus:

And here's the runner bean ('White Lady'):

I know it's blurry, but... it's going the same way, isn't it? Or am I crazy?

The only other runner bean photo I can find in my files also has a blurry background, but you can see the direction of the twining here as well:

Then I hit the internet, and looked at many photos of runner beans and pole beans, and couldn't see a difference in twining direction in any of them. I found lots of descriptions of clockwise and counter-clockwise (or mostly "anti-clockwise" since runner beans are most popular in the UK) twining, viewed from below or viewed from above (try it. It goes the opposite way), but no photographic evidence that shows a vine (technically a bine) slanting upwards from right to left rather than left to right, which I think it should. But perhaps I'm wrong. Convince me I am and that the much-reported "fact" is correct!

By the way, Malabar spinach and Siberian kiwi seem to twine the same way as all the beans.

After squinting at all these photos and running out to check your own beans, you may wish to listen to some music, so have Flanders and Swann's classic comic take on twining direction and star-crossed love, "Misalliance."


  1. So, do they twine clockwise when grown in the southern hemisphere? LOL

    1. Apparently not, but there's much internet discussion about that as well!


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