Climbers

[rarinrob]

Why do beans, peas and other climbers ascend supports in a clockwise manner? Sensible answers only please.

[wildwood]

oops... only just saw your 'sensible answers only' bit, so had to wipe my answer.

Could it have something to do with the way the sun rotates?

[rekstout]

Climbers will wrap around an object either clockwise or anti-clockwise depending upon their species. One would suppose that, within a species, all plants wraparound in the same direction because that is a component of their genetic makeup, causing them to develop internal structures which cause tendrils etc to curl in a certain direction. Could also be a conspiracy by botanists.

[SteveD]

I would assume that they follow the sun and that, in the southern hemisphere, they would ascend anti-clockwise. Imagine that you are in the northern hemisphere. Look towards the equator (i.e. look south) with the plant in front of you. The sun rises in the east (i.e. to your left) and moves from your left to your right to set in the west. If the plant follows the sun, it will tend to move in a clockwise direction. If you do the same thing in the southern hemisphere, (but this time you are looking north), the sun will still rise in the east, but will move from your right to your left, "pulling" the plant in an anti-clockwise direction.

[Dazzler]

I would tend to go with the phototropism answers too myself

[New Forester]

"Rekstout" is right -- it's built in to the plant, not from the sun rotating. They keep the same direction whichever hemisphere they're in, and also near the equator where the sun goes straight over the top. For example (having just checked in the garden), runner bean climbs clockwise, but honeysuckle anticlockwise. Once I cruelly made a shoot of each try to twist round each other -- they got very confused! (Peas, marrows, vines etc climb with tendrils, which usually wrap around what they touch, either way.)