Black Arrowhead is another winner for my zone 3 gardens, it has multiplied rapidly and flowers (and flowers, and flowers). I have it in the center of my primary garden, where it gets all day sun ... here in the north, during summer, that is almost 14 hours per day in the middle of summer, though days get shorter towards September. Every time I take a photo of 'any other daylily' near the mid-garden area, there are always Black Arrowhead flowers in the background.
Very hardy, loads of flowers - don't know about fertility, I have not done any crosses using my spiders, but it creates a nice balance against Calico Spider to its right - the dark and bright flowers have almost reverse colours and show well together.
Black Arrowhead
Calico Spider
