Q.Can I install new sod on top of old crappy grass?
My yard is a mess. Plan to follow your instructions to kill a large part of the lawn – along the outer sides of the yard – by using newspaper, then bark mulch on top. I presently have shrubs and little trees in this area so hope they will grow once I get rid of the grass. My grass is the s—s! Want to put in new sod. Can I just install directly on top, or newspaper first, or newspaper, then some fresh dirt, then the new sod?

Certified GKH Gardening Expert
I would not recommend it for new sod because the old grass will form a mat below the sod that will make it harder for the new sod to grow deep and healthy roots. When it comes to putting in new flower beds, it is ok because flowers tends to have stronger roots systems that can break through that mat, but grass has relatively weak root systems and the sod will not establish well if placed over old grass.