The perennial peonies growing in my garden are of the herbaceous cultivar variety. There is also a tree variety; which I've never had the pleasure of seeing in a nursery or yard.
Hardy to Zone 5, my peonies grow in the rock garden (full sun) and in a garden on the north side (partial sun) of the garage. Both peonies are over 15 years old, in well-drained soil with delicate pink petals. Sweetly fragrant, the plants grow to a little over two feet.
Peonies are easy care. I cut them back in the spring when the new growth starts. Most people cut them back in the fall after the plant has died back.
I remember peonies grew in the yard next to my childhood home. Two things come to mind when I think about them - first, how the blossoms drooped or lay flat on the ground and second, the icky ants crawling over the buds and up and down the stems.
After a couple of years of having the blooms fall flat, I found a fix for the first thing.
I installed a green circular, wire plant support secured by four stakes (from Gardener Supply). The stems grow up through the holes in the circular form. The green color of the support blends in with the foliage. The stems are supported by the form at mid-level. Even when wet, the blooms remain erect. With that main distraction solved, I almost don't notice the ants.