How Do They Know?

I am extending the range of my thumbergia alata as I have alot of truely ugly fence to hide. They all wind the same way through the mesh. Why?

I think it's a matter of the vine touching the object and cell growth along the stem. The cells grow longer on one side of the stem... thus making it twine around the object. Does that make sense?

One of the girls at the local school did a science project on whether vines twine clockwise or counterclockwise. She came to the gh to "inspect" my vines because I had such a large variety. Even the tendrils on a specific variety of passion vine twined the same way.
If you are trying to "help" the vines along with their twining, you must wrap them in the way they're accustomed to twine or they will unwrap and start over the right way.

Thanks Poppysue. It's just very interesting. I had sweetpeas whose tenrils all curled to the right and cucumber tendrils that went left. I will have to go out and "annoy" some vines and see what happens.

Frogsrus, I read about an experiment where a man took the support from his vine and watched it search for something to climb on. He marked where the vine was each evening and said it eventually traveled in a complete circle searching for a support to climb on.

Thunbergias are called 'clock vines' because they all wind clockwise. Or so I've read. Mine do.

judyb, well I have two otherr varieties sarted so I will run the experiment. We like experiments here. I have lots of alata seedlings coming up to practice on.

I've been paying attention to this in my garden this year, everything seems to want to go clockwise, I've had to rewrap some that I had tried to help along, I had wrapped them in the wrong direction, they didn't like it and wouldn't hang on.

That's interesting about a plant having a preference for which way to vine. Must be why some of my vines don't "take" where I've tried to push them.

THANKS!