My Happy Returns daylily was here when I moved in five years ago and has done marvelously.
They are loaded wit buds, but some scapes are yellowing and the buds are drying up. I have
not experienced this before and wonder what is wrong. I will say the plans are quite crowded;
I tried to divide a couple of years ago without much success.
I live in Lee's Summit, MO, a suburb of Kansas City, MO

I checked the drought map because that's how some of my scapes acted last year when it was 90 and dry all summer last year, but it looks like you are not under any drought stress.

So I suspect it's just overcrowding, and it might be time to divide it and reduce the size of your clump. The only other thing I can think of, going back to lack of water, is that if they were planted under a young tree, and that tree is growing larger and larger, it could be stealing water from your daylilies. Obviously, that's just a total shot-in-the-dark guess.