Can I use topsoil?
This is my second year of SFG... last year I had a 4x6 raised bed with about 8" of topsoil mixed with organic compost, and had a pretty good year. My cukes kinda tapered off toward the end, but I was getting tomatoes, peppers, and eggplant all the way through to first frost.
This year I'm expanding. I'm adding a level onto my 4x6 (to give me some more depth to work with, the soil below is almost all clay mixed with bricks and God knows what else, this being DC). I'm also making a second L-shaped bed, about 48 square feet.
Should I keep using topsoil/compost, or was I lucky to get the yield I got from topsoil last year? Would a vermiculite/peat/compost combination be any less expensive? With topsoil, my soil costs are going to easily top $150-160, for 72 square feet of garden.