I live on the edge of a salt water marsh and one corner of the backyard was severely packed with Japanese knotweed several years ago. We dug up all the roots we could for a few years in a row and the thicket has thinned out considerably. However, this thing is pernicious and it only takes a bit of root left to create whole clumps of new plants. This past summer we saw quite a few shoots coming up several feet into the yard but we were unable to take care of it. This year, I know we'll be doing some more back-breaking work digging them up. Does anyone know of an easier way to get rid of this stuff?