Peonies are a treasured addition to countless gardens, celebrated for their lush foliage and large, often fragrant blooms. Many gardeners wonder how these plants contribute to the ecosystem, particularly in supporting local insect populations. Whether a peony is a valuable resource for pollinators depends almost entirely on the specific variety and the resulting structure of its flower.
The Critical Divide: Flower Structure and Pollinator Access
The accessibility of a peony’s reproductive parts is determined by its flower form, a consequence of decades of cultivation and hybridization. Modern peonies are classified by the number of petals they possess, which separates beneficial varieties from those bred purely for aesthetic preference. The highly hybridized double-flowered and “bomb” forms, prized for their voluminous, globe-like appearance, feature an excessive number of petals.
This proliferation of petals results from the plant’s stamens transforming into petal-like structures known as petalodes. The dense, layered arrangement physically blocks insects from reaching the true stamens, which may be buried deep within the bloom or entirely absent. These full-bodied flowers offer little accessible pollen and hide the nectar reservoirs located at the flower’s base. For an insect, a double peony is essentially a closed vault with no reward.
In contrast, peonies that retain a simpler structure are excellent food sources. These types feature an open center where the functional stamens and carpels are clearly visible and easily reached. The difference between an accessible and an inaccessible flower is often a matter of genetic mutations that favor petal mass over reproductive function. This structural divide means that two peonies can have vastly different values to local pollinator communities.
Identifying Peony Types That Support Pollinators
Gardeners wishing to support insects should select peonies with visible, open centers, offering direct access to pollen and nectar. Single-flowered peonies are the most beneficial type, characterized by one or two rows of large guard petals surrounding a prominent cluster of yellow stamens. Varieties like ‘America’ or ‘Scarlet O’Hara’ are excellent choices, providing an abundant and easily reachable food source.
Semi-double peonies also provide a good compromise between ornamental beauty and ecological function. They have more petals than a single bloom but still leave the center clearly exposed for foraging insects. The Japanese and Anemone forms are also beneficial, distinguished by centers filled with modified, often pollen-producing stamens (staminodes), surrounded by a ring of larger guard petals. The Japanese variety ‘Nippon Beauty’ is a good example of this open-centered structure.
Focusing on these simpler flower forms provides the most actionable advice for increasing the biodiversity value of a peony planting. By choosing varieties with a clear, golden heart, gardeners ensure the plant is functional for the insects it attracts. This selection process counters the structural barriers found in the common, ecologically sterile, double-flowered cultivars.
Nutritional Value: Peony Pollen and Nectar
Accessible peonies provide insects with two distinct nutritional categories: pollen and nectar. Pollen is a protein and fat source, important for developing larvae and the overall health of the colony. Open-centered peonies produce substantial amounts of this protein-rich dust, which bees efficiently collect on the specialized hairs of their bodies.
Nectar is primarily a sugar solution, serving as the immediate energy source for adult insects, fueling their flight and foraging activities. This sugary liquid is secreted by nectaries located at the base of the flower’s carpels. The petals of Paeonia lactiflora cultivars contain high levels of soluble sugar and protein, suggesting the reproductive structures are rich in these compounds.
When an insect visits an accessible peony, it receives a dual benefit of energy and protein, making the flower a high-quality resource during its brief blooming period. This timely contribution is particularly important in late spring when many newly emerging insects are actively building up energy reserves and provisioning nests.
Specific Insects Attracted to Peonies
The open architecture of single and semi-double peonies makes them attractive to robust insects that are effective pollinators. Bumblebees, with their large, fuzzy bodies and long tongues, are frequent and efficient visitors to open peony blooms. These native bees are adept at collecting the abundant pollen and accessing the nectar hidden deeper within the flower.
Honeybees, though often less efficient than native cousins, also readily forage on the accessible pollen and nectar. Smaller insects, such as specialized syrphid flies, are attracted to the wide landing platform provided by the guard petals and consume the surface pollen. These insects are true pollinators, actively transferring pollen between flowers as they forage.
A notable, non-pollinating visitor to peonies is the ant, frequently observed crawling over the flower buds. Ants are not seeking pollen or nectar from the open flower but are drawn to sugary secretions produced by extrafloral nectaries located on the green sepals of the developing bud. This relationship is a form of mutualism where the ants consume the liquid and, in return, aggressively defend the bud against damaging insects.