Paeonia lactiflora, commonly known as herbaceous peony, belongs to the section Paeonia within the genus Paeonia. It is native to temperate regions of Asia and Europe. In contrast, tree peonies (e.g., Paeonia suffruticosa) belong to the section Moutan and are primarily native to China. While both are members of the Paeoniaceae family, their distinct sections reflect evolutionary divergence.
Herbaceous peonies (P. lactiflora) are perennial plants with soft, non-woody stems that die back to the ground in winter. They regrow from underground roots each spring. Tree peonies, however, are deciduous shrubs with woody stems that persist year-round, growing taller (up to 2 meters) and developing a permanent framework. Their woody structure allows them to support larger flowers and foliage.
P. lactiflora leaves are compound, typically divided into 9 or more lance-shaped leaflets with smooth or slightly serrated edges. Tree peonies have larger, glossier leaves, often deeply lobed or bipinnate, with a leathery texture. The foliage of tree peonies tends to emerge earlier in spring and may exhibit a bronze or purple tint when young.
Herbaceous peonies produce multiple smaller flowers (10–15 cm diameter) per stem, with a shorter blooming period (1–2 weeks). Colors range from white to pink and red. Tree peonies bear fewer but larger flowers (15–25 cm diameter), often with a longer bloom time (2–4 weeks). Their flowers exhibit greater variation, including yellows and purples, and may have a prominent central boss of stamens or double forms with layered petals.
P. lactiflora develops a fleshy tuberous root system used for nutrient storage, making division the primary propagation method. Tree peonies rely on woody crown roots and are often propagated by grafting onto herbaceous peony rootstock or from seeds, which may take years to flower. Their slower establishment contrasts with herbaceous peonies’ quicker clump formation.
Herbaceous peonies thrive in colder climates (USDA zones 3–8) and require winter chilling for bud formation. Tree peonies prefer milder winters (zones 4–9) and are more sensitive to extreme cold without snow cover. Both need well-drained soil, but tree peonies tolerate slightly more alkaline conditions and benefit from wind protection due to their taller, woody growth.
P. lactiflora plants may live for decades but require regular division every 10–15 years to maintain vigor. Tree peonies can survive over 100 years with minimal pruning (only deadwood removal). Herbaceous types demand deadheading post-bloom, while tree peonies need careful pruning to shape their woody structure.
