Black wrecking it .. " don't itch it" lol , only if ..
Bearinator.. It's "seed bank" is 2 to 3 years, and if it's on a river bank, that seed bank will be restocked every summer when plants further upstream drop there seeds after flowering, theres thousands on every head.. It's not helped by folk cutting it once it's seeded and throwing there problem into the river just to make someone else's problems worse.. Learn to Id it early and spray it off, but u will end up having to do it every year.