Their showy blossoms can be either single or double, while others are anemone-like, having broad outer petals with petaloids in their centers. Herbaceous peonies thrive in USDA Zones 3 to 8, and bloom profusely after a period of cold winter chill. Tree peony cultivars are descendants of P. suffruticosa , a Chinese shrub. This variety is an open, somewhat woody deciduous shrub that can reach 6 feet in height. As with herbaceous peonies, tree peonies are long-lived and resent being transplanted, so you should choose their locations with care.
Tree peonies are also more hardy to cold than their herbaceous relatives.
There are a myriad of varieties to choose from and most nurseries offer them in late winter and very early spring. The blossoms of tree peonies vary both in size and color, depending on their individual variety. Tree peonies also bloom in early to mid-spring, sporting magnificent bursts of bold color. Some nurseries also offer seedlings that are unnamed, so it's best to buy those when they are blooming so you can choose the colors you want. Peony Planting Pointers Location Peonies do best when tubers are planted in early fall, but will also thrive if planted in early spring.