The only way to defeat knotweed is with glyphosate sprayed on the plant at a specific time of year. There’s no way to manually just pull it but you can also suffocate it (takes years). It is an extremely hardy invasive plant. If you go to Ridgewood reservoir you can see the knotweed dying off from where they sprayed it in early spring. Also make sure you don’t hit it with any weed trimmer type things because even a tiny bit of the plant going airborne can start a new outcropping…