ga.prime":l17trhjf said:I see that Plenum 160 ME uses picloram as the active ingredient. Picloram has a strong residual and the manure from cows that eat grass that has been sprayed with herbicides containing picloram will possess toxic levels of herbicide. You don't want to use that manure on your garden. It's a great chemical, it just requires extra caution and forethought using it because of the residual effect. I use it to kill prickly pear cactuses and to treat cut stumps to prevent re-sprouting. It's the right thing to use for that kind of weed. You have to have a good residual, contact herbicides won't do the job.