sod over crabgrass
Here is the result so far, after 18 days. Sod was laid on top of crabgrass with no preparation whatsoever, in late August. Temps about 85, but trending downward, 78 today, 44 degrees last night. Weather was mostly dry so it turned brown, but since then I have been watering it with a hose a few minutes a day. Beginning to tack down. Looks slightly better.