My understanding is that day lilies require 6 hours of full sun to do well so being in dappled shade could be part of your problem, they flowered the first year as the flower bud was already in the bulb when you planted them but are possibly not getting enough sunlight now. Also if they have been in the same container for three years have you fed them at all and ensured they were kept watered?

Thanks for your advise. I think it is neglect. I should have watered and fed them sooner, also, although their situaton is in dappled shade; they never get the full sun.
I will be moing them when the leaves die down and see what happens next year.

Good luck Roseberry - let us know how you get on.