Please help! Our yard is infested with crabgrass! We ripped up the grass and plan to have new irrigation and new sod (fescue) put down. Right now our yard is only dirt and I can see the dead roots of the crabgrass everywhere along w some new growth that is green and flourishing. Our landscaper is going to rototill the dirt before putting the new sod down but will that be enough to rid the crabgrass? I feel like the roots will still be present and will resurface but I am new to all of this. Is there a way to spray the green crabgrass before the sod is layed or will that hurt the sod's chances of taking?