My peony plants, glorious queens of the spring garden, look ratty and exhausted by fall. This may be due to the hot summers in my area. I have seen photos of more northern growers cutting back fall-colored peony foliage that any florist would love. I can assure you no florist is buying my crispy brown stems that time of year.
If you live in an area like mine, never fear. The horrible-looking peony that you're worried might be dead will be back, and gorgeous again, next spring.
So how to take care of it now?
Besides being an eyesore in your flowerbed, those dead stems and leaves can allow fungal spores to overwinter. Cut the stalks close to the ground, making sure not to damage any shoots you can already see emerging. If you had any trouble with disease this year, it's important to remove the dead plant material from your garden altogether. Place it in the trash and don't compost it. If you haven't had any issues with plant disease this year, it may not be so very important to be so vigilant.
What about Itoh Peonies?
I've been talking only about herbaceous peonies to this point, because that's the bulk of what I grow. Herbaceous peonies die back to the ground each year. Tree peonies are shrubs and shouldn't be cut back at all. Itoh peonies, a third type of peony, are a hybrid between the two types. If you know the variety name of your peony you should be able to look up which type it is.
Itoh peonies, true to their hybrid nature, grow some woody growth and some herbaceous growth. The woody growth often has eyes that will form into blooms next year. The herbaceous growth can be discarded as shown above. The easiest way I've found to do this is to comb my hands upward through the plant wearing gloves. This removes the crumbly herbaceous growth while leaving the woody growth intact.
As discussed in Mulch for Peonies, if you've had disease problems it would be wise to remove any mulch from around your peonies and dispose of it as well.
Then, bid your peony plant farewell for the winter and leave it to the cold weather it loves. It won't need your help again until spring.