Planting bare-root peonies, often called divisions or “peony eyes,” requires careful preparation that significantly influences future success. The question of whether to soak these dormant roots before planting is common, and the answer is generally yes, depending on their condition upon arrival. Proper hydration is crucial for establishing a perennial that can thrive for decades. Peonies are long-lived and dislike being moved, making it worthwhile to get the planting process right from the start. These steps detail the proper approach to planting divisions to encourage robust growth and plentiful blooms.
Understanding Bare Root Peony Hydration
Bare-root peonies are shipped while dormant, meaning they have minimal moisture surrounding their thick, fleshy roots. While they are resilient, the roots can sometimes appear dry or slightly shriveled after shipping, making a short pre-planting soak beneficial. This rehydration acts as an insurance policy for roots that have been in storage or transit for a while.
A brief soak in cool or lukewarm water for about 30 minutes is advised to plump up the tissues. This allows the root to reabsorb water lost during storage and prepares it for establishment. The duration should be strictly limited to no more than one or two hours. Over-soaking can quickly become detrimental, risking saturation and leading to anaerobic conditions and root rot.
Site Selection and Soil Preparation
Selecting the permanent location is a long-term commitment, as peonies dislike being disturbed once established. They require a minimum of six hours of direct sun daily for a strong bloom cycle. Planting in too much shade often results in lush foliage but few, if any, flowers.
The soil must be well-drained, as the fleshy roots are highly susceptible to rot. If the native soil is heavy clay, amending it with organic matter like compost or aged manure is necessary to improve drainage and aeration. Peonies prefer a soil pH that is slightly acidic to neutral, ideally ranging between 6.5 and 7.0. Avoid planting near large trees or shrubs, as the peony’s roots struggle to compete for moisture and nutrients.
Planting Depth and Technique
The depth at which the root division is set is the most critical factor in planting bare-root peonies. Peony divisions are characterized by thick roots and small, reddish-pink growth buds, or “eyes,” which are the starting points for the next season’s stems. Dig a hole 12 to 18 inches wide to comfortably spread out the root system.
The eyes of the herbaceous peony root must be positioned only one to two inches below the soil surface after backfilling. This shallow planting depth is non-negotiable for future flowering; planting the eyes any deeper is the most common reason a peony fails to bloom. In warmer climates, planting closer to one inch is better, while two inches offers slight protection in colder regions.
To achieve this precise depth, form a small mound of soil in the center of the planting hole. Spread the roots downward and outward over the mound, positioning the root crown so the eyes face upward. Carefully backfill the hole with the prepared soil. Gently tamp the soil around the roots to eliminate large air pockets, ensuring good contact between the soil and the root tissues.
Immediate Post-Planting Care
Once the root is set and the soil is backfilled, the plant requires a thorough initial watering. This deep soak settles the soil around the roots and helps remove any remaining air pockets that could dry out the root division. After this initial watering, maintain consistent moisture without allowing the soil to become saturated.
A light layer of mulch can be applied to help retain soil moisture and regulate temperature fluctuations. Keep the mulch material a few inches away from the crown to prevent moisture accumulation and rot. The first season typically shows minimal top growth and no flowers. This is a normal period of establishment, as the plant focuses its energy on developing a strong root system.