April Shrub of the Month-Tree peony

Most gardeners are familiar with the old-fashion herbaceous peonies, but once most newbie gardeners meet a tree peony, there is no going back. The name is misleading since tree peonies are not a ‘tree,’ but more of a sub-shrub with woody stems, unlike its cousin-the herbaceous peony that dies down to the grown every winter and emerges in spring. 

Tree peonies, Paeonia suffruticosa, can grow 3-5′ tall and wide with blooms as large as 10″. They can be finicky in St. Louis. Rich, organic, well-drained soil (think compost and lots of it!) and a bit of shade are appreciated, especially in the late afternoon. Protection from winter wind is also crucial. Since they flower early, they are suspectable to late freezes, and the buds will need to be protected if frost is predicted once the plant ‘awakens’ in early spring. The results, although short-lived, are breathtaking. 

Google “Tree Peonies for sale” and be prepared for a shock. These can get pretty pricey and hard to come by locally.

Tons of cultivars are available in every shade of pink, purple, white, and red with forms of double, semi-double, or single flowers. The foliage is similar to the herbaceous peonies.

Every spring, there is confusion about peonies. What’s so confusing? Itoh peonies are a cross between the woody tree peonies and the herbaceous peonies. These are easier to find in local nurseries, but they are often sold as ‘tree peonies.’ These Intersectional hybrids have sturdier stems but go dormant during winter like herbaceous peonies. The sturdy stems prevent them from flopping after heavy rains. Itoh hybrid peonies also bloom later in the season when the herbaceous peonies are finishing and long after the actual tree peonies finish. The bloom time of Itoh hybrid peonies is also a bit longer than that of herbaceous peonies.

Tree peonies should NOT be cut back after frost. Pruning is seldom required, except to cut out dead wood or suckers in early spring and to remove spent flowers. 

What I love about this plant-the stunning flowers! The longevity of the plants, the erect flowers that don’t need support like herbaceous peonies. No ants, which sometimes frequent herbaceous peony blooms.

What’s not so great-super-pricey and hard to find locally. This is a plant for the more advanced gardener with a thick wallet and even thicker skin since they can be finicky here. Although the plant is hardy, it needs cover during late freezes, or you may lose the flowers for the season. Tree peonies are usually long-lived plants but take several years to establish, and once planted, they are best left undisturbed.

Words and photos by Jo Batzer

© Jo Batzer, garden-lou.com, All rights reserved.