Our self-sufficient bidens grow in areas where other plants won't, and bloom at a time of year when they help the pollinators the most, so I happily leave them be. By the time ours set seed we're pretty much done with using their areas anyway, so the clingy seeds are pretty much a non-issue. If I clean up that space at all I simply do so before the blooms open and all is well. I hope there will always be some bidens growing here.