I have them in 1,2-1/2 and 3 (which people call 5) gallons. I grow most of all my lilies in containers. I have a small area and I have bearded irises, roses and some lilies in the ground. I been using Ace bags of potting soil, but in the last 3 years (approx) I have been collecting pot recycle soil left in the areas from our growers. I just add bonemeal and water once or twice a week. Depending on the bulb size I will add soil about half way, plant the bulb and fill balance on container. When I repot them I find them about the same spot as I planted them.
Just had a seedling bloom yesterday, planted from seed 11-18-11 (Gold American Hyb)I purchased these from Lisa I think. I do have it written down. Got good germination and next year should have a lot more in bloom.