Peonies are popular perennial garden plants, cherished for their lush foliage and large, fragrant blooms that arrive in late spring and early summer. If you are wondering whether this garden favorite maintains its greenery through the colder months, the answer is straightforward: No, peonies are not evergreen. Their life cycle requires an annual period of winter rest, which is necessary for survival and successful flowering the following spring.
Peonies are Deciduous Not Evergreen
The Paeonia genus is classified as either herbaceous perennials or deciduous shrubs. The term “deciduous” means the plant sheds its leaves seasonally, typically in the fall as temperatures drop. This is in contrast to evergreen plants, which retain foliage year-round.
All peonies enter winter dormancy, a process that conserves energy and protects the plant from freezing temperatures. The plant’s energy is pulled into the root system to sustain it underground until warmer weather returns. This natural cycle of shedding above-ground growth is a survival mechanism. The type of peony determines what happens to the stems and leaves during this time.
Herbaceous Peonies Winter Dieback
The most common type, the herbaceous peony (Paeonia lactiflora), exhibits complete dieback in the fall. Once the first hard frost arrives, the foliage turns yellow, brown, and collapses to the ground. This signals that the plant’s above-ground life has ended and it is entering dormancy.
The stems and leaves completely die back, leaving only the underground crown and tuberous roots. This period of cold is a requirement for the plant to set flower buds for the next year. The roots must experience several weeks of chilling temperatures, typically between 32 and 40 degrees Fahrenheit, for successful spring blooming.
Tree Peony Stems During Dormancy
Tree peonies (Paeonia suffruticosa) are classified as deciduous shrubs, meaning they have a permanent woody structure. They are the exception to the complete dieback rule and often cause confusion regarding the evergreen question. Like herbaceous peonies, they lose all their leaves in the fall, but their stems remain standing throughout the winter.
These woody stems withstand cold temperatures, protecting the dormant buds that will produce next spring’s leaves and flowers. The plant’s energy is stored within this woody framework and the roots, allowing it to survive the season. Cutting these stems back is not recommended, as it removes the wood where the following year’s blooms are already set. Tree peonies provide structure in the winter landscape, even while completely dormant.
Preparing Peonies for Winter
Practical care for peonies in the fall centers on hygiene and protection during dormancy. For herbaceous peonies, the dead foliage should be cut back to about an inch above the soil level after it has died back. Removing this material prevents fungal diseases, such as botrytis, from overwintering and infecting new spring growth.
Tree peonies should not have their woody stems cut back; only remove dead or broken wood to maintain their structure. A light layer of organic mulch, such as straw or shredded leaves, can be applied around the base of young or newly planted peonies after the ground freezes. This mulch primarily prevents frost heave, which can push the root crown out of the soil, rather than insulating the plant from the necessary cold. Dispose of all removed foliage in the trash instead of composting to limit the spread of disease.