I am repairing my lawn that is mostly clay and i want to know if i can put a thin layer of topsoil over some?

Question

patchy shallow areas that need to be filled and then seeded

Answer 1

Be careful with that you want to make sure to try and mix it all a few inches down. If you don't the grass and other things you plant may not develop good root systems. They would want to stay in the top soil and not venture into the clay. They usually go the path of least resistance. So mix it up and good luck!

Answer 2

We live here in Michigan and there is a lot of heavy clay under our grass.  But I remember when the sod was laid. The fellows put down a good 1-2" of topsoil over the clay, raked it in good, laid the strips of sod over it, and had us water it well for days. They said that the topsoil would provide a good base for the grass roots to grip.

Note: If you put down a lot of thin topsoil with nothing to "bulk" it up, it'll sink on you as it settles with rain, snow, and you walking on it. You can mix in some clay that you can get for free at any new-home construction site--just bring your own buckets and a shovel.