Anything is doable if you work at it hard enough. There is an article online that I wanted to attach but can't find, will keep looking because I know we referenced it on one of the peony FB groups. It was written by Don Hollingsworth and in it he referenced conversations with a man that was was growing them in zone 9 or 10. He claimed the trick to it was to force dormancy by cutting them back in fall, regardless of the fact that the temps don't really drop enough.
While looking for the article written by Don I found this by Cricket Hill.
https://crickethillgarden.word... It might give some useful tips.
I grow peonies now in zone 8a AL. There are certainly challenges and I'm still working on overcoming them. First off—peonies aren't going to prosper in seriously hot summers without at least afternoon shade. Peonies have a storage root, that storage root provides moisture and nutrients to the foliage and flowers. In more temperate areas this isn't a stressor but they work so much harder to do the same thing where it's super hot. As the soil temp starts to drop in cooler areas the plant starts growing roots instead of above ground growth, doesn't work anywhere near as efficiently in areas that stay hot so much longer so the roots don't increase as well or at all, hence the plant doesn't get bigger/better as fast, if at all. If the root is worked had enough trying to keep the plant hydrated with no chance to grow feeder roots it will flat out fail and die.
My advice to you is to find a place in your garden where your peony will be shaded from the time it gets hot in early summer until it cools as much as your area does in fall. Bare root planting in spring will not be very successful for you because the storage root will have no little feeder roots established to resupply, potted maybe will work if you give it afternoon shade. I'd personally go for an Itoh as they need less cold hours or Lactiflora that has an early bloom time to start and purchase it from a reputable grower to be planted in fall. Even fall planting will be challenging, they tend to start growing above ground when the planting temps are still warm, don't know how to avoid that—I experience it in my garden as well. Probably best to watch and cut back fall growth to encourage it to stay dormant until the following spring.
