Paeonia lactiflora, commonly known as the Chinese Peony, is a herbaceous perennial. This means its soft-stemmed growth dies back completely to the ground each winter, and it re-emerges from its underground root system in spring. It is not a tree peony, which maintains a woody structure. This plant has a specific growth cycle: a period of vigorous spring growth, spectacular flowering in late spring to early summer, followed by a crucial period of photosynthesis and energy storage in its foliage and roots throughout the summer and fall to fuel the next year's blooms.
For optimal health and flowering, Paeonia lactiflora requires a specific location. It thrives in full sun, meaning a minimum of 6-8 hours of direct sunlight daily. While it can tolerate very light afternoon shade in extremely hot climates, insufficient sunlight will result in weak stems, reduced flowering, and increased susceptibility to fungal diseases like botrytis. The plant also requires protection from strong winds, which can easily damage its large, heavy flowers. Good air circulation around the foliage, however, is essential for preventing disease.
The foundation of a healthy peony is its soil. Paeonia lactiflora demands well-draining soil; its fleshy roots will quickly rot in waterlogged conditions. It prefers a fertile, loamy soil with a neutral to slightly alkaline pH. When planting a bare-root division, timing is critical. The ideal window is in the fall, allowing the plant to establish its root system before winter dormancy and a spring growth surge. The most crucial step is planting at the correct depth. The "eyes" or growth buds on the root crown must be buried no more than 1-2 inches below the soil surface. Planting too deep is a primary reason for a peony's failure to bloom.
Watering should be deep and infrequent to encourage the roots to grow downward. Provide about one inch of water per week, more during periods of extreme heat or drought. Always allow the soil to dry out slightly between waterings. Overhead watering should be avoided to keep foliage dry and prevent disease. For nutrients, Paeonia lactiflora is not a heavy feeder. An annual application of a balanced, low-nitrogen fertilizer or a top-dressing of compost in early spring, as the red shoots emerge, is typically sufficient. Excessive fertilizer, especially nitrogen, will promote weak, leafy growth at the expense of flowers.
After blooming, deadhead spent flowers by cutting the stem back to a strong leaf. This prevents the plant from wasting energy on seed production. However, do not cut back the foliage until it has died back naturally in the fall. The green leaves are essential for photosynthesis, creating the energy reserves stored in the roots for next year's growth. Once the foliage has yellowed or been killed by a hard frost, cut the stems down to ground level and remove them from the garden to minimize overwintering disease spores. Apply a light mulch after the ground freezes to prevent heaving from freeze-thaw cycles, but remember to pull it back in early spring.
