I have no information on the reblooming ability of either Hemerocallis hakuunensis or Volcan Fuego - so to that extent I am no further on.
Each autumn I bring inside any daylily that has been suggested to be endodormant (need to experience a period of cold to start growing again); I have yet to find any that do not grow once they are brought inside and given appropriate growing conditions. Originally I brought them inside in mid-October. Plants I have brought inside between then and the end of December have all started to grow relatively quickly.
The information I have about rebloom in daylilies indicates that nearly all daylilies rebloom in the appropriate growing conditions either in locations in California or in locations in Florida.
The current information I have is that some seedlings that have never experienced growing conditions that would signal them to stop growing/go dormant do stop growing but then after some period of time they start to grow again without any change in their growing conditions.
Other information I have is that there are some seedlings that never experience cold but do experience the condition most likely used to signal that they should go dormant (short days-long nights) and they do stop growing but after some period of time they start growing again without experiencing any cold.
There are also some seedlings that never experience cold, do experience short days, stop growing and do not start growing again for quite a long time. Those might be possible candidates for daylilies that can use a period of cold to start growing again. However, they clearly do not have a mandatory requirement to experience cold to grow again.
Stout made observations that suggested that Hemerocallis middendorffii might be a daylily that required a period of cold to start growing again (be endodormant in the autumn). The plant I had purchased as middendorffii did not require cold to grow and did not behave in the same way when growing inside as Stout found. It may not be middendorffii. I have another plant of middendorffii from a different supplier on order for delivery this spring to try again.
It may be that true classical endodormancy was infrequent in daylilies even originally and that daylilies have since been bred to have even less.
Or it may be that daylilies have never needed to experience cold temperatures to start growing again, only cool temperatures, such as say below 50F (10C) and that they experience those early in the autumn or that they only need a very short period of cool temperatures. This year I will test some plants in late August and early September by bringing them inside and giving them the appropriate growing conditions.
I have Stella and Tetrina's Daughter growing inside now. In a few weeks I may try giving them short days to see if I can force them into dormancy and then if they do go dormant I will try to get them to grow again (without experiencing even 50F temperatures) by giving them long days. Stella is one of the cultivars described as not surviving for very long in Florida. The assumption is that it needs to experience a period of cold to grow or bloom. However there is another possible explanation for why Stella may not survive for long under Florida conditions and that is poor growth due to stress caused by long periods of high temperatures. Researchers have found that Stella did not require cold to grow or bloom.
