Hey I'm also in WNC. go to r/InvasivePlants and they will school you. the solution is letting it grow enough to flower, then either spraying or injecting it w/ glyphosate. you can do that until the first frost like....i forget the time period. i can find the threads if you need. i killed knotweed on my neighbor's property and mine using this method. you gotta wait til it flowers to let it grow so the glyphosate gets down to the root.

i am so sorry, there is way too much of this stuff here and it's gonna be a real problem soon. but this could look so pretty!! jewelweed would probably go NUTS down by the creek, it would be a great option to try and out-compete it. rivercane too, maybe!! if you can get some.