A lush, green lawn can be created quickly by laying sod. But clay soil must be properly prepared. The addition of organic matter and correct placement of new sod can turn a clay surface into a wide expanse of healthy grass that can last years, given the proper care.
Prepare the clay soil for the sod. Test to find the specific characteristics of the soil using a soil test kit from a garden center. Amend the clay soil with organic matter, such as compost, and coarse sand to improve the movement of nutrients through the soil. Break up the clay using a segmented roller and then spread a layer of compost 3 inches deep and till that into the top 6 inches of clay. Next place a 3-inch layer of sand on the soil and till that into the top 6 inches.
Add phosphorus and potassium fertilizer in amounts as determined by the soil test. Compress the soil surface slightly.
Lightly moisten the soil and then lay the fresh sod. (Sod should be no more than 24-hours old.) Roll out the sod in straight lines across the surface of the clay soil. Stagger the ends of the sod so that the joints on adjacent rows are not even.
Fill any cracks between pieces of sod with topsoil.
Push a lawn roller filled about a third of the way with water over the completed surface of sod to press the sod firmly into the soil. This should level the sod and extend the roots securely into the soil.
Keep the sod slightly wet for three to four weeks to give it an opportunity to take root. Slowly reduce watering time for two to three months. Then water the sod on a normal lawn-care schedule.