I don't even have to go outside to see the lilacs are blooming, my phone rings constantly. Little old ladies (bless their heart they are a large part of my business) calling to tell me that it's too late to apply Pre-M. How do we put these concerns to rest once and for all? The way I understand it is the Crab Grass seed germinates when the soil temperature is 60 degrees at 2 inches deep. I'm not sure if that's average daily temp or a one time shot. However, I don't believe it has anything to do with the darn lilacs. Anyone got the real answer? Thanks.