Peonies are beloved for their vibrant blooms, but many gardeners are unsure about how to prune them correctly. This guide explains the best practices for trimming different types of peonies, ensuring healthy growth and long-lasting beauty in your garden.
Types of Peonies and Pruning Techniques
Peonies can be broadly categorized into herbaceous, tree (or shrub), and intersectional hybrids. Each variety has specific pruning needs, so understanding these differences is crucial.
Herbaceous Peonies
Herbaceous peonies, the most common type, die back to the ground every winter. They regenerate in the spring from buds located on their thickened rootstocks. The pruning process for herbaceous peonies is similar to that of most perennial plants: cut the plant back to ground level in late winter or early spring, just before new growth begins. Some gardeners prefer to trim them in the fall after the stems have dried, but it is generally better to wait until spring. The dead foliage provides natural winter protection for the root buds.
However, if your peonies suffer from fungal infections, such as the leaf spot disease Septoria paeonia, early pruning in the fall can help reduce the spread of the disease. Look for round, brown spots with a reddish-brown border on the leaves—these are signs of infection.
Intersectional Hybrids (Itoh Peonies)
Itoh peonies, or intersectional hybrids, are a cross between herbaceous and tree peonies. These plants feature a unique combination of both woody and herbaceous growth. Pruning these peonies is similar to herbaceous varieties, but it’s important to leave the small, woody stems attached to the plant. These stems often contain buds that will sprout new growth in the spring. However, just like herbaceous peonies, most of the new growth will emerge from the root buds.
If your intersectional peonies lose their old, woody growth in the spring, don’t worry—this is a normal part of their life cycle and does not harm the plant.
Tree (Shrub) Peonies
Tree peonies are quite different from their herbaceous counterparts. These plants do not die back to the ground each year; instead, they develop woody stems that persist year-round. Most tree peonies do not require regular pruning, and they will naturally grow larger and more impressive over time. However, there are a few exceptions:
- Encouraging Branching: If your tree peony has only two bare main stems, cutting them back in the spring can encourage new branching. You can prune the branches back into older wood if needed, as tree peonies will sprout new growth from this older wood if conditions are right. Be aware that cutting back significantly can result in a year without blooms.
- Broken or Damaged Branches: Tree peonies have brittle branches that can break under heavy snow. If this happens, simply cut the damaged branch back to a healthy bud or branch. If the plant’s structure becomes uneven, consider a more substantial prune in late winter to balance it out.
Tree peonies can tolerate significant pruning and will sprout new shoots from their root system and older wood if they are healthy and well-established.
Pruning Tips for Healthy Growth
Pruning is essential not only for shaping peonies but also for preventing diseases and encouraging new growth. Regularly removing spent blooms, especially on tree peonies, can help improve the plant’s appearance and encourage better flowering in the next season. However, it’s essential not to over-prune—each type of peony has specific needs, and cutting too much can stunt growth or even harm the plant.
Conclusion
Pruning peonies may seem daunting at first, but with the right techniques, you can keep your plants healthy and thriving for years to come. Whether you’re dealing with herbaceous, intersectional, or tree peonies, understanding their growth habits and pruning requirements will help you create a beautiful, flourishing garden.