There are two types of peonies that are generally grown in our gardens: Paeonia officinalis or herbaceous peony, which are perennials that grows to a height of 60 cm to 1.2 meter and die back to the roots with the first killing frost of the year and Paeonia suffruticosa or tree peony, that reaches a height of 1.20-1.80 meter and grows as a shrub and leaves woody stems behind when the leaves drop each autumn. Colors available for herbaceous peonies are white, yellow, cream, pink, rose, and deep red. Tree peonies come in colors such as yellow, pink, white, rose, crimson, scarlet, purple, and deep purple. Herbaceous peonies are classified in 4 major groups according to flower form: single, semi-double, double and anemone-form. Tree peonies have single to double flowers
Peonies like sunny locations, although they will grow and produce good foliage in shady locations, the flowering will be sparse or non-existent. Well-drained soils is best for their growth, but they will tolerate a wide range of soil types. Their best growth is in soil deep and rich in organic matter so this may require adding organic matter: coarse sphagnum peat moss, well-rotted manure, or similar material to the soil before planting. For best flowering select an area that receives sunlight at least 6 to 8 hours per day and plant where there is good air movement to reduce the chances of having disease problems.
Planting, transplanting and dividing peonies are best done in early fall but may be done in spring as soon as soils are workable. Prepare the ground ahead of planting 1 or 2 weeks by spading deep and incorporating fertilizer through this depth. Once the planting site has been selected and the soil prepared, the peonies can be planted. Dig a generous hole, large enough to accommodate the roots, and incorporate aged organic matter in the bottom. Select root divisions with at least 3 eyes and set so that eyes are 5-7 cm below the surface of the soil and the plants at about 1 meter apart. After planting, the soil around the plants should be thoroughly watered. If the planting is done in the fall, it would be a good idea to mulch the plants with 5-7 cm of organic material like: straw, coarse sphagnum peat moss, shredded bark, wood chips, or something similar. Mulching the first winter is usually desirable and in cold climates winter mulching is necessary if there is little or no snow cover.
Support is often required for tall, double hybrids. Staking peonies is a good idea, especially if they tend to flop over by mid-summer. To stake them most effectively you should start this early in the growing season, when the first red shoots are showing. You can use commercial supports, which consist of a wire grid on legs, the legs are pushed into the ground over the peony shoots and the stalks then grow through the openings in the grid. If you don’t find to buy those supports just make some of your own by some sticks and wire.
Peonies may be left undisturbed for many years. In general, they usually do not need to be divided for 10 to 15 years, but if you want to propagate them, carefully lift the clump and wash away the soil to expose the eyes. Use a clean, sharp knife to divide the clump into sections making sure that each section have three to five eyes and good roots. Replant the sections immediately and if this is not possible keep new divisions in a shady area and do not allow them to become dry.
You can also propagate peonies from seeds. Sow the seeds in containers outdoor in autumn or early winter, but you must have patience because some of them might take 2-3 years to germinate.
Peonies may be also grown in pots, but they will do well only in large, well-draining containers where that can accommodate their huge root system. They need to be fed often, like once a month and protected from very cold temperatures over the winter.
Let the plant die back in the fall and don’t trim the plant back just immediately, because after blooming, peonies offer lovely foliage which will allow the roots to store the nutrition that plant needs for next seasons flowers. Wait until the first hard frost, then cut stems back to the ground. If the plant has experienced plant disease, you can trim it back to the ground by removing and disposing any diseased leaves and stems.
The presence of ants on peony blossoms is neither beneficial nor harmful to the plant so there is no need to spray them. Ants are attracted to peonies because of the nectar they produce while in bud.