Are Tree Peonies Splittable?

Tree peonies are a popular and fragrant plant in gardens, but they rarely require division. However, if you want to break a mature plant into several smaller ones or move an existing one, it is best done in late summer or early fall. All peony types should be divided in the fall after flowering, well before the first frost hits. The process involves digging up the entire plant, dividing the root ball, and replanting the sections.

There are two variants of propagation for peonies: vegetative propagation (dividing rootstocks) and generative propagation (propagating by seeds). The best time to divide peonies is in the fall, typically in late September or early October, as this timing allows the plants to establish roots before the ground freezes. Dividing peonies during their dormant season, which is typically in the fall or early spring, helps ensure they establish new growth.

In zones 4 to 7, September is the best month to divide or move peonies, and it’s also a good time for many other perennials. Large peonies can be divided if additional plants are desired, but they can be left undisturbed in the garden for 50 or more years. They can be dug up and split like herbaceous peonies but usually need less divisions. They can also be propagated by cuttings that are grafted onto certain plants.

Herbaceous, garden peonies are longlived and do not need regular division, unlike many garden plants. They can be left for years, even decades, to get on with their growth.