Hardy to zone 3 or 4, tree peonies bloom several weeks ahead of herbaceous peonies. With huge silky blooms and attractive deeply cut foliage, they are attractive all season. Once established, they are easy to care for. Unlike herbaceous peonies that die down to the ground, tree peonies have woody stems with soft branching in the spring where the flower buds appear. Bloom colours range from reds and pinks and purples, to white and yellow and soft orange shades.
Tree Peonies can grow 4 to 6ft (1.3 to 1.8m) tall and require a sunny spot, preferably with some afternoon shade, good drainage and fertile soil.
Plants are shipped bare root in early fall or as potted plants in the spring.
Tree peonies are usually grafted on to herbaceous roots. Positioning the tree peony so the graft is about 15 cm (6 inches) below the soil surface will encourage tree peony roots to grow. Because they will stay in place for many years, the planting hole should be at least 1 ft. (30 cm) deep and wide and backfilled with soil amended with compost. Water the soil as you plant to ensure no air pockets remain.
Keep the soil evenly moist, especially with new plantings. A thick layer of mulch around the plant (not touching the stems) will help retain moisture and give winter protection.