I thought I was the only one who put a layer of soil in my styrofoam boxes then the top 1/3 I used a potting soil mix! I got many grape boxesa few years ago and now either put newspapers leaves or plastic at the bottom of the box. I like plastic best since it holds the moisture better! Here is a guy that shows you how its done similar to the way I do it! I usually add a 1/2 inch of sand to seperate the two mixes and add the seeds on top of the wet sand! When I pull out the seedlings to transplant they come out easy with the sand clinging to the roots!