Peonies are cherished garden flowers. With proper care, they can thrive for many decades, becoming a lasting garden feature. They are popular due to their impressive display and low maintenance once established.
Types of Peonies
Peonies are categorized into three types. Herbaceous peonies are the most common, with soft stems that die back to the ground each winter. Their flowers typically bloom in late spring to early summer.
Tree peonies feature woody stems that do not die back annually, forming a shrub-like structure. These types often produce very large flowers earlier in the spring than herbaceous varieties. They create a permanent garden presence and can grow quite tall.
Intersectional, or Itoh, peonies are a hybrid of herbaceous and tree peonies. They possess strong, woody stems that die back partially in winter, similar to herbaceous types, but produce large, uniquely colored flowers like tree peonies. Itoh peonies are also known for their extended bloom period.
Planting Peonies
Successful peony growth begins with proper planting, with fall being the best time. Planting in late autumn allows roots to develop before the ground freezes, preparing the plant for spring growth.
Peonies thrive in full sun, requiring at least six hours of direct sunlight daily. Good air circulation helps prevent fungal diseases. Soil should be well-draining, as peonies do not tolerate soggy conditions, and ideally possess a neutral to slightly alkaline pH. Adding organic matter improves drainage and fertility.
For herbaceous peonies, planting depth is important; the “eyes” or buds on the root crown should be planted no more than one to two inches below the soil surface. Planting too deeply is a common reason why peonies fail to bloom. Tree peonies, often grafted, require the grafting union to be placed about four to six inches below the soil line to encourage root development. Proper spacing (three to four feet apart) ensures room for mature growth.
Caring for Peonies
Once established, peonies are low-maintenance. Consistent care promotes healthy growth and flowering. Regular watering is important during dry periods and active growth. Avoid overwatering, as excessive moisture can lead to root rot.
Light spring fertilization supports the plant as new growth emerges. A balanced, low-nitrogen fertilizer is recommended, as high-nitrogen formulas encourage leafy growth at the expense of flower production. Herbaceous peonies, especially those with large, heavy blooms, often benefit from support structures like rings or stakes to prevent flopping.
Deadheading spent blooms improves appearance and redirects energy from seed production. In the fall, after the first hard frost, herbaceous peony foliage should be cut back to the ground. This helps remove disease spores and pests, promoting plant health. Tree peonies generally require minimal pruning, usually only to remove dead or damaged branches.
Common Peony Challenges
Peonies are robust, but gardeners may encounter challenges. Lack of blooms is a frequent concern, stemming from planting too deeply, insufficient sunlight, or immaturity. Late spring frosts can also damage emerging flower buds.
Fungal diseases like Botrytis blight (gray mold) can affect peonies in humid conditions. Symptoms include brown spots, fuzzy gray mold, or white powdery coating on leaves. Good air circulation and proper sanitation help prevent these issues.
Ants are often observed on peony buds but are harmless. They are attracted to sugary nectar and do not damage the plant. Leggy growth (long, sparse stems) indicates insufficient light, suggesting a sunnier location.
Peonies as Cut Flowers
Peonies make magnificent cut flowers. Harvest herbaceous peony blooms when buds feel soft and show color. This allows buds to open fully once cut, providing a longer vase life.
When cutting, use sharp shears and leave at least two sets of leaves for plant health. Remove any foliage that would fall below the waterline. Placing cut stems in fresh water with floral food helps them hydrate and last longer.