My lilies are potted in dishpans with kittie litter. I used timed release fertilizer, but they were slow to take off and I added tomato spikes.
I tend to overplant lilies like I do other pots. I have 4 tuber in most of them and all the tubers had buds. I discarded any without buds.
I did remove 2 dishpans this week that had no buds because the tanks are beginning to be over crowded.