Winsorw, welcome to ATP!
Here's a secret, kinda...most daylily growers will give you fulva daylilies because they don't want them in their gardens because they grow TOO well. The "ditch lilies" are good for preventing erosion in ditches and they are pretty. As far as taste, I have tasted most of my 1200+ dayliles, and I believe the yellow blooms are far more tasty. "Hyperion" is a cheaper, older, tastier yellow daylily that many nurseries still sell. It's available online from many sellers for $5 or so. If you can find a daylily grower near you, see if they will let you walk through the beds, tasting the different colors. You will see there is quite a variance in flavor.
I've never cooked mine, I just snack on them the way you would a fresh cucumber or pepper. They kind of taste like cucumbers to me. They also add color and flavor to salads!