I've got several feral patches in the vicinity of my yard, though I haven't much propagated them except to spread a few clumps with my shovel. I've got a
thread here showing pictures of the tubers, if you're curious what those look like:
https://permies.com/t/34208/soil/Edibles-feral-Day-Lilies-growing
I find the buds very tasty and I especially like the lower portion of the stems, the part that is white like a leek at the base. The tubers also taste good but they are pretty small to be messing with in my opinion.
One word of warning: some of the herbals and wild food guides I consulted contained vague imprecations against eating "too many" day lilies. Not much useful was on offer as to what was "too much" or what the negative consequence might be. I ate them in small quantities with no problems. Then came the day I decided to make a substantial salad of day lily stems, redbud flowers, and
native pecans. About twenty day lily stems went into the salad. It was beautiful, but ... how to put this delicately? The salad passed through my system at a high velocity, picking up and taking with it most of the
water in my body as it went.
But it was
a very pretty salad: