It won't sprout until it gets watered - but once you start the watering and sprouting begins you have to keep it up or the seeds die very quickly.

Where do you live?

What kind of grass seed did you use?

Northern Iowa - Shade mix from our local Bomgaars, which I've used with success at a different house that we lived at, but that was seeding new lawn, not over seeding. We caught some rain last night, looks like we'll get some Wednesday and Saturday. I can hook the hose back up and the sprinklers, I think. We got below freezing last night, but not for too long.