Dont' apply a post-emergent during the transition (green-up) of C4 turf. It WILL stunt it. Also, don't apply a glyphosate product OT of turf anywhere near green-up. Use corsair or revolver instead. These are things that we know but I don't think they've been stressed enough. I'm sure that I'll learn a lot more over the next couple of years. This is something that I enjoy and that I know, but I don't KNOW it, if ya know what I mean. One thing I do know, playing damage control isn't fun.