WesternBiker
Member
Indeed - it is incredibly invasive and the rhizomes (the enlarged roots from which it grows) can go down 10ft. Eradication with herbicide normally takes 2-4 years. In Japan, it's controlled by an aphid-like bug and a fungal disease.The problem is that that it can regrow from surprisingly small pieces - a stem as little as a couple of centimetres long is enough to regenerate a whole new plant. Often times the only way to deal with it is to remove every trace that you can see and then take the soil away and pass it through an incinerator to kill anything still alive in it.
That all said, not only is it not harmful to humans, the young shoots are edible - a sort of lemony rhubarb taste, and in Japan and Vietnam young stems are prepared a bit like asparagus. And packed full of vitamins, minerals and antioxidants. Best not to try eating one that's been treated with herbicide, though...