I am going to try to work with the extension agent when I get the time. Hope to be able to control it with out having to use long lasting herbicides. I seem to remember reading about clopyralid, best I remember it is very slow to degrade. Thanks for the post, I know I have my work cut out for me in trying to control this mess, but I will certainly try to make clopyralid a last choice. I am fortunate that I only had a small section invaded by this plant so far in one of my beds, only half a dozen plants or so. I dug them out as carefully as I could, but as you know the roots are so fragile it is almost impossible to get them the first few tries. The house my parents left us however really has a serious invasion of Mugwort, in the flower beds and the lawn, just no way to dig it out over there. I will try a broadleaf herbicide that is faster to breakdown and hope I can control it with the supervision of the county agents instructing me on the spray schedule.
I did find this info I remembered reading about clopyralid: I do a lot of composting of grass clippings and was concerned about picking up grass that had been treated with it.
http://ohioline.osu.edu/aex-fa...
