I’ve got about 30 pea plants in the garden. Most of them have somehow found the support fence and are now growing up it. The fence is about halfway between two rows of peas spaced about 12 inches apart and runs north and south. The peas on the south side of the fence are leaning northward, and have begun to wrap their little vines aroung the fence, and the peas on the north side of the fence lean southward and are also working their way up the fence. It has been my experience that no matter where you plant a pea it will find the nearest thing to grow up.
Why?, How?
I’ve got two thoughts on it…
1). The vines that wrap around things get blown around until they hook something. Assuming there is wind.
2). The plants can detect shade, therefore, whatever side of the plant there is shade there must be something to hook. They grow away from the Sun, sort of.
I’ve seen speeded up footage of growing vine plants. They seem to circle around and around as they grow out of the ground, appearing to grope for something to grab onto; when they find something they corkscrew around that while they climb. It’s really quite freaky to watch. But of course because the movement is inperceptible in real time you never notice it.
In other words, the tendrils grow outwards in a spiraling motion (circumnutation) until they contact something, and then the plant grows towards the contact (thigmatropism). The tendrils that go “exploring” and don’t find anything are either retracted or die and fall away:
In my experience with string beans… they will climb and cling like a pea plant…that, if I try to move some tendrils so they go off in the direction I want…those tendrils will die off. They have a mind of their own, and we ‘farmers’ ain’t changing anything. Nature is so cool.
The tendrils on pea plants really do whip around like grappling irons (albeit rather more slowly) - when they touch something, they bend around it and start contracting, spring-like, actually pulling the plant closer against the support.
Other plants do similar sorts of things; in the wild, Swiss Cheese plants (Monstera spp) are huge and vigorous climbers that produce fruits containing thousands of tiny seeds; these fall to the gound and break open, than each seed produces a long slender stalk that grows toward the largest/nearest shadow (which in the native habitat is usually a tree).
I was just in the garden a few minutes ago and it seems as if one of the peas really went out of its way to gain access to the fence. Almost like it started growing in only that direction on purpose. It had to grow across the dirt first and there doesn`t seem to be any extra branches going out in other directions to explore. Maybe this one just got lucky, however, the shade effect would explain this too.
