That's pretty normal for peonies, at least around here. The leaves in that top picture look like they got sunburnt; the second picture looks more like just general late season peony leaves. No need for any kind of spray or fertilizer. Just leave them be.

Thanks so much!!

Is it OK to ask a kinda-related question even though this isn't my thread?

The question: Are there any peonies that keep decent foliage for a while, or is it inherent in the plant that it blooms and then promptly naps? I'm guessing "inherent in the plant" but I have one unnamed rose (that is, I don't know its name; I'm sure it has a name) that has foliage so early and so late that it's almost like it's evergreen in my climate, so I wondered if peonies might also have similar variance in foliage.

I think it depends on your climate. I have 58 peonies in my care (public garden) and they all look cruddy by Labor Day.

Thanks! I was threatening to put in a row of peonies, with something in between them that will have foliage. If there were ANY peonies with sustained foliage, even if they're boring, I was going to use peonies between the peonies. :)

I like to front my peonies with good foliage plants ;)

Sadly, mine will have to go down a wide row in my vegetable garden, so the sad rotting foliage will be visible--one row over from the sad rotting foliage of the Oriental poppies. :). I'm debating maybe punctuating all of them with candytuft to help a little.