Since all my herbaceous peonies are rescued, I had to plant them in partial shade. That is, because my garden is small, and the sunniest spots are reserved for roses, poppies and three peonies. As the time passes by, I've figured out that three peonies are doing better in partial shade. I believe that is because they prefer a bit of shelter in our climate (Zone 5b.)
Thus, I had two herbaceous peonies blooming in almost total shade (e.g., no more than 2 hours of direct sun light.) I believe one of them was White Wings and the other was Sarah Bernhardt. In general, single flowering peonies peonies do better in partial shade than doubles. All of them will need more time (i.e., additional two or three years) to start blooming in partial shade.
A couple of years ago, I rescued one creamy-white peony from the neighborhood. I admired that plant for many years; it was huge. Just when I'd come to rescue it, I realized that the plant was growing in almost total shade. Cannot explain how. Anyway, I had to dig through the piles of bricks and concrete (developers!) to save it. The roots broke into five or six pieces, which I gave to other neighbors. The piece that I took was planted in partial shade, but it gets a lot of morning sun. Hopefully it will bloom again this year and we will be able to id it.
Another rescuee was growing under a huge Norway maple tree; total, total shade. I noticed a couple of dry flowers that were still there when I dug it up. Not sure re the id, but it might be Karl Rosenfield or Red Charm. We can try to id it this year. Hopefully, it will bloom.
On the other hand, there ate some peonies that really need more sun. Several years ago, I got an old variety that we couldn't id. The plant was really nice when it was growing in the full sun, but the neighbor wanted to get rid of it, so I took it. It's in partial shade in my garden, but it obviously needs more sun - the plant simply stopped blooming. I'll have to replant it in the fall.
