I have awesome results growing Asiatic lilies in pots. But I use styrofoam coolers decorated . They multiply so good in the styrofoam that I have to thin them out and put them in the garden.
The styrofoam and good soil is a perfect environment for them in my experience.
Debra, because the pots are so big I picked up to large clematis Nelly Moser that I am going to use. I will see how it works out.