This article explains the caring for peonies from planting to propagating.
There are two types of Peonies: the Tree Peony and Herbaceous. Peonies are a member of the Buttercup Family (Ranunculacea), related to the Clematis, the Columbine and the Trollius. They are hardy in cold climates and not likely to fare well in a warm climate such as Southern California or Florida.
The Herbaceous Peony is very easy to grow and is best planted in the fall from September 15 until the first freeze. Root divisions fare better than planted peony seeds. Generally available at nurseries, a three to five eye root division is the perfect choice for general planting. When planting in the southern climates, the root divisions need to be in a partial shade area. In northern areas, the peonies require full sun. Planting will need to be in an area with well-drained soil. The soil does not need to be light in texture. The depth of the ground for planting should be about one and one-half feet. The soil should be tested to assure that it is neutral. A soil with slightly acid medium would suffice. The roots should be planted shallow, keeping the eyes no more than one and one half inches below the soil surface. Allow two to three feet distance between the plants for expansion.
The period between the sowing of the seeds and resultant plants that are mature and blooming can be long. The seed may not reproduce itself and may not be identical to the parent plant. If you do decide to sow seeds, they should be sown in boxes, frames, or even in the open ground, with a thin layer of dead leaves in a shady area. The germination process is slow.
With proper care, the peonies may be left undisturbed for up to twelve years. During the summer, weeds should be kept to a minimum. During the growing season, applications of a complete fertilizer should be added. At the beginning of the summer, a top dressing of organic matter is beneficial. To prevent seed formation, it is necessary to cut off the side buds when they first appear. This process will allow the terminal bud to have strength for producing a large flower. Staking is necessary for the varieties with heavy double flowers. Faded flowers should be cut to prevent seed formation.
The herbaceous perennial should be divided every few years. Propagation can be more effective from older plants by means of suckers or side growths that appear all around the parent plant. In autumn, propagation by division is the best standard method of multiplication. This method of division is probably the most reliable. One easy method of division is to cut thru the crown of the plant. Each piece of the root division will produce a bud that will grow a new plant of the same variety. Each of the divided sections should have at least two eyes, although three would be more preferable. The divisions can be planted in a permanent position or grown in pots for a year or so.
Peonies are not immune to disease. Botrytis sometimes causes a sudden wilting of stems and foliage. Afflicted parts should be cut and burned. Nematodes may be serious. The symptoms of Nematodes are a lack of bloom and a dwarfing of the plant. When dividing the root be very careful to examine to see if these tiny microscopic nematodes are present. Consult your local plant nursery for handling disease control.
The Tree Peonies usually grows from three to four feet. The trees are not as easy to grow as the Herbaceous Peony. The experienced gardener knows that it is not always easy to produce magnificent plants. The culture of Tree Peonies is full of uncertainties, difficulties and even disappointments. Success is very gratifying when beautiful shrubs are blooming and thriving. Tree Peonies do best in slightly alkaline soil. Planting Tree Peonies is the same as specified for Herbaceous Peonies. The union between the scion and the under stock should be set about an inch below the surface of the soil. Propagation is by grafting and is a matter for the experienced specialist. It is too slow and too complicated a process for the amateur to attempt. Propagation from seed is also neither quick nor easy. Tree Peonies remain expensive due to the difficulties of propagation. When the Tree Peonies have completed the blooming process, they will enter a period of lethargy and the stems will remain bare. The care of the Tree Peonies is as for the Herbaceous Peonies.