If so... do they live (in good health) forever?

Or do they peter out after a while?

Mine aren't looking so hot. I do feed and water them, but even the ones that I top-dressed with a generous 2" of compost this spring have more dead leaves than live ones.

Is this normal? Or are they sick?

I think, like most perennials, daylilies need to be divided every 3 to 5 years to stay healthy.

I never do anything with mine and they stay healthy and bloom every year. I've been in this house 3 years now and will probably separate some next year, as they have spread every year since we moved in.

I agree. They are very hardy but need to be divided.

Hmmm... as I think of it, they did seem to improve for about three years before then declined.

Here in NY - where we will probably be frost-free for most of September yet - do you think there's still time to divide them this season?

If you divide them, let them air out for a day or two so the "injured" part can dry out and "heal" the part where you've separated. Otherwise, they could get mouldy and slimey!

(and die)

Absolutely, Daylilies can survive almost anything, you could divide now and have time for them to recover before frost.

I agree with the comments above! I think they'll like to be divided and should do fine! This hasn't been the best year for mine (I divided last year) but it has been extremely dry and hot after a very cold winter (for us...) so I think it's been a reaction to the unusual weather possibly.

i dont do much with mine except divide once in a while

I have just toss them to the side not have time to replant and they rooted themselves. They will be fine. :roll: