As suggested I would kill the crabgrass with liquid CG killer. At the end of
August, early September, I would core aerate, top dress with compost. Wait 2
weeks after the aeration, then overseed.

"Guitarist511" wrote:

Since it is Aug already and hot here in NJ, what can I do now to stop
the weeds and crab grass. I did the Scotts steps but seem to have had
some bad luck this year. My front is about 5% crab grass and the back
is about 50/50 with grass to weeds. Also, when is the correct time to
overseed and can I get the back yard back into shape over the next
couple of years by overseeding?

Thanks