Winter cold is not required for bloom in any daylily I have tested whether it was registered as "dormant", "semi-evergreen" or "evergreen". I have tested quite a few daylily cultivars including one that has been described as having to be put into a fridge to flower in warm winter locations and others that have been described as not flowering in Miami and others that have been described as no longer flowering because of climate warming.
That is different, in a way, from what happens if a daylily that is capable of becoming a certain type of dormant (endodormant) before winter is allowed to do so. That daylily may not sprout again for a very long time if it is kept warm but Stout found that they would sprout again without experiencing winter cold. I call those buds "stalled"; if my memory is correct Stout called them "repressed".
I have tested daylilies that have been left outside long enough so that they have become endodormant and then were brought inside. Those daylilies sprout very quickly inside but stop growing at about 1" high. They have stayed that way inside for at least six months.
Taking a leaf from evolution and the possibility that during all of prehistory, plants may have had to contend with times when the expected winter never happened, natural selection may have selected for plants to have alternative ways to grow and flower if winter should have, but did not occur. The simplest, most obvious possibility is for such a plant to sprout when it finally experiences a spring/summer environment. The differences between winter and spring/summer are that spring/summer has longer periods of daylight (longer days), higher temperatures and higher intensities of light.
Every endodormant daylily cultivar that I have tested by giving the stalled buds a few days of high intensity light (even though much lower than natural spring/summer sunlight), longer lengths of light (longer days - I gave them continuous light to account for the light intensity being nevertheless much lower than sunlight) and room temperature has sprouted and gone on to flower.
