We have the same in our garden its all paving at the mo, we are going to get part of it up and have grass down!

But thats not the point, where we used to live we had a big back garden and there was a border which was too wide so we got some turf, before laying it we dug over the soil and i sprinkled some grass seed (just in case lol), stamped the ground back down and then layed the turf on top making sure it went to the edges we wanted, never walk on fresh layed turf as it can damage the roots (so i am told) water in. then water in the evenings. fingerscrossed things should be ok.

Good luck! x