Mid summer, just as the thistles were heading out.. Residual takes out next years crop. 18 month residual before you can begin to introduce forbs. Any sooner, and youre wasting your money as they wont survive..
Im relatively new to growing/raising forbs. This is my third attemp at native wildflowers over my lifetime, the first two of which were aborted. In this world of instant gratification, a native forb stand barely stands a chance to begin with..
Im really, really new at herbicides, and specialty herbicides, mostly flying by the seat of my pants in a reactive stage, rather than pro active, which is not a good thing, for the most part.
Im sure there are other herbicide experts here that hopefully will chime in as far as timing is concerned.