Portland, Maine - 3 years ago we added a retaining wall around our front yard. The construction killed almost all of our grass allowing crab grass to move in and really takeover. The past two springs I have tried to attack the crab grass by digging up all the dead crab grass from the previous year and reseeding - the new lawn starts but doesn't seem to be strong enough and quickly gets taken over by the crab grass. I keep a bag on my lawnmower to try to keep the crab grass from spreading but it doesn't seem to matter. How should I go about fixing this problem this year? Also, when pulling up the dead crab grass I found quite a few grubs could this be adding to my problem? Thanks for your help!