This is an idea that Becky and I were discussing on another thread. The hope is that it will help people, especially daylily newbies, with selecting daylilies appropriate for their climate (since foliage habit is not a reliable indicator). It won't be perfect because not all climates with a specific zone will have the same experience. Zones are based on minimum winter air temperatures which mostly relate to woody plants above ground, don't take into account summer conditions, or how often the winter temperatures hit the bottom of the range each year in a given area. Nor will it take into account snow cover or consistency thereof, or the use of winter protection such as mulch - this could be stated though. To make things equal, I suppose Canadian contributors should use their USDA zone rather than the Canadian system (which actually takes more climate factors into account).
I'm also not sure how useful it would be to compare the European equivalents since USDA Zone 8 or 9 in the southern UK, for example, being further north than parts of Canada will not have the same daylength, light intensity or summer weather as those same zones in North America. Maybe our ATPers from other countries might want to start their own thread/s in addition?
Anyway, I would say that to qualify for these favourites by zone that the plant should have easily got through at least one year in the reporting garden otherwise it hasn't really experienced the climate. It shouldn't have struggled through the winters either.
I'll start the thread for USDA Zone 4 separately from this intro, hopefully someone from each of the other daylily growing hardiness zones will start theirs. Becky is starting Zone 9.
Zone 4:
The thread "USDA Zone 4 Favourite Daylilies" in
Daylilies forum
Zone 6:
The thread "Zone 6a Favorite Daylilies" in
Daylilies forum
Zone 9:
The thread "USDA Zone 9 Favourite Daylilies" in
Daylilies forum