I have a roughly 1 1/2 acre prairie I am working to restore. Some work has already been done-there is already some good Forbes, but hardly any grasses, and a lot of early successional, weedy prairie species present. My main invasive species issue is Vetch. There is a lot of it and since it is early in the season it is very small right now with not a lot around it. I want to spray it while it is small, with Glyphosate; however, I just ordered a seed mix I want to inter-seed with this spring. How much time should I allow after I treat the vetch to broadcast the seed? How long can I really wait to broadcast the seed? I was thinking I could maybe wait until the end of May, but that might be pushing it. Any helpful hints are appreciated. Thanks!