One more thought, from just looking at the growth in my pond a few minutes ago~
I noticed this last year and just remembered it now.
Lilies grown in a good depth of dirty fish-poopy gravel (no soil), have bolder variegation and hold it better than my soil-raised lilies. I can see the difference midsummer with my Graziellas that are raised both ways (Please, no gravel bad/ gravel good debate!
I'm just making an observation).
For really big, fast-growing plants with bountiful blooms, nothing beats enriched clay soil though.
Also, I'd like to express my thanks to those who have responded, and a general thanks to site admin and the wonderful crew of participants here. Your generosity with your time and knowledge is simply a joy to witness.
Thanks,
Laura