Peony leaves are notched.
Every one (20) of my mature peony leaves are all notched, but not the smaller ones close to the ground. What causes this? Is something eating them?
Utah County Utah flowers: annuals and herbaceous perennials
Nothing is wrong with your peonies. But, yes, something is eating them. I can't be 100% sure but evidence points to root weevils which famously cause notched leaves as they eat.
Here is a solution for the adults :
Adult feeding, as evidenced by leaf notching, can be controlled with sprays of certain pyrethroid insecticides such as bifenthrin, cyfluthrin, and lambda-cyhalothrin. These should be applied to the foliage and it can also be useful to treat areas at the base of plants, where they rest during the day. Control may be improved if applications are made late in the day or in evening, as the weevils become active and move onto the plants after dusk..
You can control the larvae by applying natural nemotodes to the soil. Just visit your local greenhouse and they can point you in the right direction.