Peonies are herbaceous perennials that die back each winter and regrow from their roots every spring. While autumn is traditionally the ideal time to plant divisions, planting bare roots in the spring is a viable option to establish these long-lived garden staples. A bare-root peony is a division from a mature plant, consisting of thick, fleshy roots with small, pointed buds emerging from the crown. These buds, called “eyes,” represent the next season’s stems, leaves, and flowers.
Selecting the Site and Preparing the Soil
Peonies require a permanent location in the garden since they do not tolerate being moved once established. Selecting the right site is important, as a peony can thrive and bloom in the same spot for decades. The plant needs a minimum of six hours of direct sunlight each day to produce abundant blooms, though those in warmer climates may benefit from some afternoon shade.
The soil must be well-draining because peonies are intolerant of standing water, which can cause the fleshy roots to rot. If the native soil is heavy clay or extremely sandy, amend it with organic matter like compost to improve both fertility and drainage. Peonies are heavy feeders, preferring rich, fertile soil that has a neutral to slightly alkaline pH.
Before planting, loosen the chosen area to a depth of at least 12 inches to allow the roots to expand easily. Working compost or aged manure throughout the planting area, rather than just the immediate hole, will provide a slow release of nutrients. Good air circulation is also beneficial, so avoid planting too close to large trees or shrubs that compete for resources.
The Critical Planting Process
The planting depth of the bare root is the most important factor for successful peony bloom. Begin by digging a hole 12 to 18 inches wide, but not excessively deep. The goal is to accommodate the spread of the roots while ensuring the buds are positioned correctly near the surface.
Place the peony root in the hole with the thick, fleshy roots pointing downward and the small, pointed “eyes” facing up. The root should be settled so that the eyes are covered by no more than 1 to 2 inches of soil. Planting the eyes deeper than two inches is the most common reason peonies fail to flower, often resulting in lush foliage but no blooms.
For gardeners in warmer zones, the planting depth should be closer to one inch or even half an inch, as the plant needs to feel the chilling temperatures of winter to set flower buds. Backfill the hole with the prepared soil, gently firming it around the roots to eliminate air pockets.
If planting multiple peony roots, space them 3 to 4 feet apart to allow for mature growth and maintain good air circulation. Proper spacing helps prevent fungal diseases. Marking the planting location with a label or stake immediately after planting is advisable, as the bare root will not show significant top growth right away.
Immediate Aftercare and First Year Expectations
Once the bare root is correctly positioned and covered with soil, a thorough watering is necessary to settle the soil and fully hydrate the roots. Deep watering ensures that the roots make contact with the surrounding soil, which is crucial for establishing the plant. After this initial soaking, watering should be done regularly during dry periods for the first year to help the plant establish a strong root system.
New peony roots should not be fertilized in the first year, as high-nitrogen fertilizer can burn the tender, developing roots. The organic matter added during soil preparation provides sufficient nutrients for initial growth. Too much nitrogen may also encourage leafy growth at the expense of flower production in subsequent years.
Applying a light layer of organic mulch around the planting area can help conserve soil moisture and suppress weeds. Keep the mulch away from the immediate crown and “eyes” of the plant. Mounding mulch directly over the crown can mimic planting too deeply and prevent future blooming.
Patience is required in the first growing season, as newly planted bare roots focus their energy on developing a robust underground system. It is common for a spring-planted peony to produce only foliage and no flowers in its first year. Most peonies require two to three years of establishment before they begin to bloom freely.