The Tree Peony (Paeonia suffruticosa) is one of the most glorious shrubs known. It's huge, silky flowers have the same general shape as that of herbaceous Peonies. Their range of color runs from pure white through pinks and reds into lavender and yellow, with shades that are unknown in their herbaceous kin. Their exquisite blooms are born on a 4�5ft frame, above which as many as 50 flowers may be carried on a mature plant. Their late May display is one of the highlights of spring.
Tree Peonies grow best in full sun or partial shade (required in the South and warm areas of western Zone 9) and evenly moist but well-drained soil with a pH close to neutral; they fare poorly in the desert Southwest.
Hardy zone 4-9
Best grown in deep, fertile, medium wet, well-drained soil in full sun to part shade. Tolerant of summer heat. Add compost as needed before planting. Larger shrubs appreciate some shelter from strong winds. Unlike herbaceous peonies, the stems of tree peonies (which are woody shrubs) do not die to the ground in winter and should not be cut back after frost. No pruning is required, except to cut out dead wood or suckers in early spring. If plants become leggy, a moderate pruning in early fall can be done to shape plant and encourage additional growth on the lower part of the plant. Remove spent flowers after bloom. These long-lived plants usually take several years to establish, and are best left undisturbed once planted. Moreover, plant roots go deep and transplanting can be difficult. Appreciates some winter protection in USDA Zone 4 and the colder areas of Zone 5.