admmad said:
The plants arrived in August and were put into pots dependent on the size of the plant, especially the crown and roots. The pot diameters would have been from 6 to 9 inches.
That's not much different from what I used although I think they would have been less than 9". I do have one currently outside in a pot sunk in the ground that has been there for several years and it is in a pot nearer to 9". It did flower this year too. When I've done this before, and it's years ago now, it would most likely have been with plants I purchased potted, at least some of them from local daylily sellers so they wouldn't have been shipped.
I don't know why it would have worked for me and not you, unless it has to do with the origin of the plants, and/or the media used, and/or winter rainfall frequency or amount, and/or difference in native soil. It is sandy loam here, am I correct in thinking you're on clay?