Tree peonies have been grown for their large, colorful flowers for thousands of years. The blooms range from pure white and creamy yellows to rich reds and deep purples. Unlike herbaceous peonies, which die back during cold weather, tree peonies grow as woody shrubs, reaching a height of 3 to 5 feet. While tree peonies can be propagated from seed, air layering and root division, grafting is usually the method of choice.
Select a branch to act as the scion to be grafted from woody growth about 1 year old. The scion should be collected in late summer after the next year's buds have formed.
Remove about 5 inches from the end of the branch with a sharp knife. If the scion has a terminal bloom bud, remove it.
Select an herbaceous peony from which to take a root. Lactiflora peonies are an excellent root source.
Dig up the plant and remove any soil from the root. Cut off the top of the root squarely. If the root is long, cut it to about 10 inches.
Soak the root stock and the scion for one hour in a sanitizing solution of 1 part chlorine bleach to 20 parts water. Wash them off with clean water. Sanitize all utensils with alcohol prior to grafting.
Trim the cut end of the scion with two equal cuts to resemble a small pointed wedge.
Cut a thin slice off the cut ends of the root stock. Cut a wedge in the top edge of the root stock that resembles the cut end of the scion.
Insert the wedge end of the scion snugly into the cut in the root stock.
Wrap the graft with a grafting band. Cover the graft with Parafilm tape to form a waterproof barrier.
Place the new graft in a resealable plastic bag with a damp paper towel. Label the bag with the scion and root cultivar names.
Put the graft upright in a warm area (70 degrees F.) for four to six weeks. After this time, check the graft to see if it has healed.
Plant the graft in a location that has full sun or limited shade. Plant the graft so that the joint is about 2 inches underground. Mulch the graft with straw or leaves.
Water the new growth to keep the soil moist, but not wet. If buds form, remove them. As the plant continues to grow, carefully dig around the root to remove the grafting band. Recover the graft with soil.