Sir,
No one should ever plant Japanese Knotweed, even for survival purposes. The stuff is so aggressive that it can tear a house off its foundation in a matter of months. I’ve read of at least one case in England that required the top ten feet of soil be dug out and hauled away to keep it from sprouting again. If your readers find this invader someplace and can eat it, wonderful. But I pray they don’t make the mistake of thinking this would be a great addition to their survival garden. – Kathryn D.