I apologize in advance if this has been discussed on a thread in the past, but I need some advice on pre-emergent weed killer/blocker for a bermuda lawn. I have a few broadleaf weeds, but its mostly grassy weeds like crabgrass and nutsedge. I've found pretty good success with post-emergent weed killers, but I've never done a pre-emerge and I haven't had much luck finding any in places like Home Depot and Lowes. Any suggestions? Also, I've heard different opinions on this, but when is the best time to put the pre-emerge out? Fall or Spring?