They just sit there. They don't grow but they don't die either. I waited over 6 years for one bloom.
Same with the Datura, just sits there. I have a yard full of plants, some of which are not even supposed to grow in my zone and they are all doing fine. Total strangers stop by to talk about plants.
Maybe it's like true love and you only get one shot at it. I am okay with only having one daylily in my life - it is the best daylily in the world to me.