I think a good garden daylily to me is similar to what Michele said. I like to see one that clumps up nicely with tons of scapes and a lot of bloom. I may or may not use it in hybridizing. I have several seedlings that I would call good garden daylilies. They may not be cutting edge but they present a lovely presence in the garden. I have kept several clumps of these seedlings for that reason.