Tom,
Potting Iris. I have been doing this for about three years (potting for sale). I use 1 gal "Trade" pots. I used to bury the pots to keep them from having wide temp ranges as I thought that would be an issue. Katie from Stoney Creek Iris does not bury her pots and she is an hour North of me. The negative to burying is that you would need to "wash" the pot when getting it ready for sale. I start selling in late February and early March and a dirty pot does not look good and may be a hard sell. Katie has even brought in pots to an event that still had snow on them. If you just use top soil, the pot can get very heavy and hard as concrete. I try to use a mixture that works well for the plant and is easy to carry (current formula is 1/3 top soil, 1/3 potting mix, 1/3 peat moss). Neither of us worry about where the pots are facing and I have had very little loss.
I had slightly over 250 pots last year in the "for sale" catagory, of which 155 were of sufficient quality/maturity to in fact sell. Had at least another 100 to 125 pots in the nursery/ICU trying to get small nubs to grow. More loss with that group because of size and heath of the plant.
