i've been reading this forum for the last couple of weeks, and have decided that i want to go organic on my lawn.

i have a problem with what i think is quack grass. i've been able to get rid of most of the crab grass that we have. half of our yard is covered with this thicker grass that won't die off (from chemicals... before i started reading here).

we want to over seed this fall with KGB, i've changed the watering to longer and more infrequent. would over seeding help with the quack grass? or is it best to kill it off and start over from scratch?