Bob,

Bob, if you want to keep living in Baton Rough you should change to oleander or any other zone 9 plant. If you cant do without your peonies, I suggest you think about moving back to Iowa.

They will grow anywhere but need about 400 hours chilling to bloom. Even then the buds must be at ground level not below. Call your county extension and ask about your local chilling hours. Al

Here in Atlanta we can grow some of the old double stand-bys like Festiva Maxima, but I fear Baton Rouge is a little too hot even for them. I do know as a general rule, the more single they are, and the earlier the bloom season, the better they do in heat. That may mean that you have to search out some of the species Peonies (harder to find) instead of the more common cultivars you were used to in Iowa.
I have spent a good deal of time in various states, and in every state and clime "Zone lust" is a common gardener's disease. Pennsylvanians wish they could raise Gardenias and Sarasotans long for Hostas. An species of equal loveliness to Peonies, that loves Louisiana, is Camellia japonica. Your friends back in Iowa would kill for these beautiful rose-like blooms that you can enjoy on Christmas Day in Baton Rouge!