All daylilies registered on or before 1980. This is a “rolling” date which extends by ten years every decade, i.e. in 2020, the date will change to 1990.
Some members of the AHS collect and display historic dayliies. Look under AHS Display Gardens on the AHS Home Page menu. Historic Daylily Display Gardens are listed within their own AHS Regions and are additionally distinguished with salmon colored cell backgrounds.