I attempted to put in a new lawn in late May/early June. I got a good amount of germination from the new grass seed, but I also got a ton of crab grass. I want to be able to reseed in September but I do not know what my next step should be. Should I leave the crab grass alone and hope the new grass doesnt get choked out or should I attemp to treat the entire area with a chemical and hope only the crabgrass dies.

Any suggestions would be great.