This is an OLD one, but has to be in my top 5.
Penny's Worth
It is the first daylily to bloom for me, and the last daylily to bloom for me. I have had scapes of it on my Thanksgiving table before and that is saying something in central Ohio. It reblooms and reblooms all summer. The foliage is so small and fine, it looks like a clump of grass. It increases well, and I have small clumps of it all through my mixed perennial border.
In this picture, it is planted in the sun just at the edge of the shade from a witch hazel. So it is backed by shade perennials such as small hosta, pulmonaria etc. The blue in the picture are some volunteer violas Johnny Jump Ups.
I think Penny's Worth only gets about 10" tall.
