The plant is big and beautiful and perhaps the greediest water hog that has ever lived in my yard. Not only that, when there isn't enough water in this arid climate, Her Hugeness wilts as if to announce to passers-by what an awful garden-tender I am.
I have dug up the big black roots again and again. I've covered them with weed barrier and inches of mulch. I've even put pavers on top of them to try to get them to go away. Now all I have left are these little shoots and I'll stay after them until they are gone. Maybe I'll go so far as to eat them!