Gardening Articles: Flowers :: Perennials
Chinese Tree Peonies (page 3 of 3)
by Kasha and David Furman
Pests and Diseases
Pests are at a minimum on tree peonies. In the Northeast, rose borers (the same insects that bore into cut rose canes) sometimes afflict older plants, and in spring, carpenter bees act as one of many pollinators. You can detect them from spring to fall by a 1/16-inch hole in the woody stems. If you find such a hole, poke a wire inside to kill the larvae, and seal the hole with clay or white glue. In other parts of the country, thrips and nematodes can be pests. Trap or hand-pick thrips and destroy all plants with nematode galls (visible on the roots).
Tree peonies are sometimes infected with the botrytis fungus. It occurs during wet, cold weather in spring and fall. Cut below the infection and remove and destroy affected parts. In the fall, remove all leaves, infected or not, to prevent any botrytis from overwintering underneath the plant.
Tree peonies have many wonderful qualities: ease of cultivation, relative freedom from pests and diseases, widespread hardiness, and flowers acclaimed for hundreds of years for their beauty. We invite you to visit Cricket Hill Garden (in Thomaston, Connecticut) in late May, when you'll see more than a hundred varieties of mudan hua in bloom. You'll learn that paintings and photographs are only pale reflections of the real thing.
A Glimpse of Other Tree Peonies
Besides Chinese tree peonies, three other types have been in cultivation for many years in the West. The Japanese types are common, European and American hybrids are rare, and Itoh hybrids are extremely rare.
Japanese tree peonies are descendants of Chinese plants brought to Japan in the early 17th century. The Japanese, with their own aesthetic principles, chose to grow and cultivate plants with only certain characteristics: single or semidouble flowers, plants that stay under 6 feet, and most important, flowers with little or no fragrance.
Hybrid (European and American) tree peonies were first devised about a hundred years ago, first in France, and then in the United States. The parents were species from China, yellow-flowered Paeonia lutea (of Tibetan origin), and some unnamed Chinese or Japanese cultivated varieties. Thus, yellow is the characteristic undertone color in many of these flowers. In the second generation, many less desirable characteristics of the original hybrids were eliminated (such as small or down-facing flowers), and flowers of great beauty were bred. From P. lutea, all of these, even darker colors, have an almost translucent undertone of yellow and a fragrance of lemon vanilla.
Itoh or Intersectional hybrids. There is some evidence that Chinese tree peonies and herbaceous peonies (P. lactiflora) are closely related. About 40 years ago, a Japanese breeder, Itoh, was able to hybridize a few cultivated varieties of each kind. The resulting plants had the leaf and flower characteristics of a semidouble tree peony but died to the ground each fall -- a major characteristic of herbaceous peonies. In recent years, American breeders Anderson and Hollingsworth created flowers with a whole range of colors (deep yellow and violet) not seen before in tree peonies.
David and Kasha Furman are the owners of Cricket Hill Garden -- peony heaven -- in Thomaston, Connecticut.