Sounds like a great combination. Here in Alabama we can't grow peonies (or tulips or lilacs), but irises do very well and even are found at old homesites, where the original care takes have been gone for 50 years or more. Finding good combos that bloom at the same time as iris requires a practiced eye since the bloom season here for everything in spring is so short, but irises go well with the later blooming dogwoods, they come after the red buds and bloom at the same time as azaleas. The azaleas however, tend to steal the show. Some irises bloom at the same time as the first roses.
