"Plants do not have a January 1 start date for their growth"
I have seen a chart showing the different GDD base temps for various plants and wondered if we had one for daylilies, 42F I'll have to remember that. They do show a general consistency in bloom time/season and the garden has a definite flow from beginning to end, but with so many factors to consider in FFO pinpointing exacts seems near impossible. I also compare FFO's during the season with a friend 3 hours south of me. It is amazing sometimes the difference between my FFO for something and his, sometimes mine bloom first.
There have been a few reports of folks seeing scapes starting and a few early blooms in the south....we still have a long way to go.