Peonies are prized for their magnificent, often fragrant flowers, but their show is relatively brief. To create a visually appealing garden bed throughout the growing season, selecting companion plants with contrasting foliage textures and forms is essential. The bold, glossy, and sometimes deeply dissected leaves of peonies provide a perfect backdrop for plants with finer or more architectural foliage. Ornamental grasses, like Fountain Grass (Pennisetum alopecuroides) or Blue Fescue (Festuca glauca), offer a soft, wispy texture that sways gracefully in the breeze, creating movement and contrast next to the substantial peony mound. The spiky, upright form of Iris or the broad, heart-shaped leaves of Brunnera also provide excellent textural and formal diversity, ensuring the garden remains interesting long after the last peony petal has dropped.
A primary goal of companion planting with peonies is to extend the visual interest of the garden border. By choosing plants that bloom before, during, and after the peony's display, you can achieve a succession of color. Spring-flowering bulbs are ideal precursors. Tulips and Daffodils emerge and bloom in early to mid-spring, their foliage often maturing and dying back just as the peony foliage expands to conceal it. As peonies finish their bloom in late spring to early summer, the stage can be handed over to later-flowering perennials. Catmint (Nepeta), with its long season of lavender-blue flowers, and Salvia, with its striking flower spikes, are excellent choices to carry the display into the heat of summer, preventing a lull in the garden's performance.
The most successful plant partnerships are built on compatible cultural needs. Peonies thrive in well-drained soil and full sun (at least 6 hours daily), requiring minimal supplemental watering once established. Their companion plants must share these preferences for sun exposure and soil moisture to avoid stress or disease. Drought-tolerant, sun-loving perennials are therefore the best candidates. Russian Sage (Perovskia atriplicifolia), with its airy blue flowers and silvery foliage, thrives in the same hot, sunny, and well-drained conditions. Similarly, Bearded Iris, Coreopsis, and Sedum (Stonecrop) are all plants that enjoy a similar environment and will not compete aggressively with the shallow-rooted peony for water or nutrients, allowing both plants to flourish.
While not a primary consideration, some companion plants can offer subtle benefits in terms of garden health. Peonies are susceptible to botrytis blight, a fungal disease that thrives in stagnant, humid air. Planting lower-growing, airy companions around the peony's base can help improve air circulation, reducing the humidity around the crown and lower leaves. Aromatic herbs like Lavender or Sage may also help deter certain insect pests with their strong scent, providing a layer of protection through interplanting. The strong fragrance of many peony cultivars can also help to mask the scent of more vulnerable plants from pests, creating a mutually beneficial relationship.
