It’s considered a noxious weed in most areas, so the “garden police” would be your local county who can fine you in addition to cost for removal on your property anywhere you’ve allowed it to spread. Where I am at it keeps getting spread by flood waters and taking over the entire riparian zone and spreads from there. I would hope people are just trying to troll and aren’t seriously considering planting this intentionally. How about some kuduz while you are at it?

Oh, I know about the stilt grass.. Tackling that and the garlic mustard have been all consuming. I moved into my house last fall and have been dealing with years of neglect this past spring and summer. I have no idea what that plant with the white flowers is so I just assumed the worst (knotweed). I'm out currently but will post pics of the other plants when I get home. I have managed to find some beauties in between the weeds like goldenrods, asters, and lance coreopsis growing along the woodland edge (where that pic was taken) so maybe it's another native wildflower? Getting hopeful!

Neither photo is Japanese knotweed. But the first IS a knotweed (aka smartweed, jumpweed) and looks like Persicaria virginiana.

floral_uk z.8/9 SW UK 2 days ago Have you fixed the price? Over here JK could be grounds for a reduction. Could be? Could be? Based on my reading, that is the understatement of the year. https://slate.com/technology/2019/05/japanese-knotweed-invasive-plants.html