Weed stems blowing in the wind do indeed create micro tears in the stem cellular structure. When repairing the cells, the plant will repair and then add an extra layer of collagen at the point of repair to 'prevent' the structure from breaking down again.

Stems are like bones....you will never break a bone in the same place twice. The repair site is indeed thicker than the unbroken part.

I think in addition to the winds, Bobbong is correct in that light is the other factor affecting girth of stems.

Other than that, is the usual genetics, nutes and environment. I think it all plays a role, even if in a minute degree.
HARDDON Reviewed by HARDDON on . Best way to thicken main stem? I've only heard of having a fan blow on them but I'd like to know what you guys think. Rating: 5