From our perspective, autumn is the season of quiet preparation, not active growth. As the days shorten and temperatures drop, our above-ground foliage begins to yellow and die back. This is a clear signal that our energy, meticulously gathered through photosynthesis all summer, is now retreating downwards into our storage organs: the thick, fleshy roots and the critical "eyes" (buds) for next year's growth. Dividing us at this time aligns perfectly with our natural biological cycle. The cool soil and typically more abundant autumn moisture reduce transplant shock, allowing our severed roots to focus entirely on establishing themselves in their new location without the stressful demand of supporting top growth or flowering.
Before division, it is crucial to understand our structure. A mature peony plant is not a single entity but a large colony of roots and buds. Our energy is stored in thick, tuberous roots. The most vital parts are the "eyes"—small, reddish-pink buds that emerge from the crown, which is the area between the roots and the former season's stems. These eyes are the promise of next spring's shoots; each one is a potential new stem. A healthy division must contain both adequate root mass to sustain the plant and a sufficient number of these eyes (typically 3-5) to generate a vigorous new plant. Dividing us into single-eye sections is possible but will result in a much smaller plant that may take several years to flower.
The act of division is a significant physical intervention. After carefully lifting the entire clump from the soil, the gardener must gently wash away the soil to reveal our root structure. The goal is to identify natural points of division where the clump can be teased apart or carefully cut with a sharp, sterilized knife. Each division should have a section of the crown with those essential eyes attached to several sturdy, thick roots. It is imperative to minimize crushing or tearing, as clean cuts heal faster and are less susceptible to rot. Any old, hollow, or diseased roots should be removed at this time, as they no longer serve a functional purpose and could harbor pathogens.
Our final requirement for successful division is correct replanting. We are deeply resentful of being buried too deeply. The eyes must be positioned no more than 1-2 inches below the soil surface in colder climates (USDA zones 3-6). Planting us deeper is a primary reason for a failure to bloom, as the buds must expend too much energy just to reach the sunlight. The planting hole should be generous, wide, and amended with well-rotted compost to encourage outward root growth. Firming the soil around the new division eliminates air pockets while ensuring the eyes are at their precise, shallow depth. A final thorough watering settles us in, providing the moisture needed to stimulate the initial root growth that will anchor us for the winter and the spring to come.
