Becky, I'm in 9b and on a barrier island. I have had great success keeping evergreen daylilies for decades in my garden. I do grow them in boxes with really good soil. Our beach sand is not their cup of tea. My new box in the front yard is doing very well, even though I just planted it last week.
My only criteria for daylilies is that they are true evergreens to grow here. The front box will probably have some plants that are labeled evergreen, but have a touch of dormancy. They will be the plants that fail!
From my database, I still have five daylilies (out of a total of 48 plants in the garden) that I purchased from November 2008-January 2011.
