I'm planting a potato bin of sorts (just an oval of chicken wire, with straw around the edges to keep the soil contained within the 'bin'), but I'm having a hard time deciding what to fill it with. I've seen so many different suggestions on GW and throughout the web. I know it needs to drain well and be light/fluffy/not compacted, but I'd love to hear a tried and true 'mix' with proportions.

I'm thinking some combination of topsoil, peat moss, pine bark mulch (as in 5-1-1), mushroom compost - or skip the compost and just use some of the DynamitePlus CRF that I have here from my 5-1-1 mix.

Also, how thick a layer of soil mix should be placed down below the seed potatoes? 6"? 12"?

*I'm using sprouted, organic red potatoes from the grocery store as my seed potatoes if that makes any difference on depth, etc.