There are two types of peonies: paenonia officinalis and its hybrids (also known as herbaceous or garden peony) and paeonia suffruticosa (also known as the tree peony). The following directions will cover cultivation requirements for the more familiar herbaceous peony, as they are almost indestructible and have few insect or disease pests, making them perfect for the beginning gardener. Herbaceous peonies are classified according to the number and shape of their petals. There are five classifications: single, semi-double, double, anemone and Japanese. All have the same cultivation requirements.
Plant peony tubers in early fall (mid to late September to early October). Your peony will emerge and flower the following spring.
Choose a peony tuber that has three to five "eyes." Eyes on a peony tuber are just like eyes on a potato--reddish buds from which stems and leaves emerge. Eyes are only on one side of peony tubers and should be planted up, facing the top of the hole.
Select a spot in full sun with fast-draining soil that will give your peony enough room to reach its mature size. If you don't have a spot in full sun choose a spot that receives six to eight hours of sun daily during the growing season (March through September).
Dig a hole three times as wide and deep as the peony tuber.
Mix compost into the soil that was removed from the hole. The goal is a soil-compost mix that is friable, which means that you can easily insert your hand into the mix and feel no large clumps of soil. The soil-compost should appear "fluffy" and resemble brownie mix but will form a ball and hold its shape if you take a handful and squeeze.
Add the soil-compost mix to the hole until it is just wide enough for the peony tuber, three to four inches deep.
Place the peony tuber in the hole with the "eyes" up. Adjust the soil-compost mix under the tuber until the peony tuber is one to two inches deep. Cover with the remaining soil-compost mix and water deeply.
Apply two to three inches of organic mulch over and around peony tubers after planting and after stems and leaves have died in fall.
In mid-spring, remove mulch to allow shoots to emerge. Once shoots have emerged reapply two to three inches of mulch around the shoots to conserve moisture.
Fertilize your peonies in spring when shoots are three to five inches high with either commercial 10-10-10 or 5-10-5 fertilizers or compost. Peonies only need fertilizer once a year. Using more may compromise flower production.
Apply commercial fertilizers according to package directions. Mix three to four big handfuls of compost, about six cups, into the soil around the emerging peony shoots.
Water your peony every other to every two days during the growing season (March through September). Peonies should receive one to two inches of water weekly.
Water your peony tubers over the winter in dry areas or areas with mild winters. Water on days where daytime temps are over 40 degrees.
Support peony foliage using peony rings. These are metal grids that stand one to two feet high.
Position the support so that it is over the emerging peony growth. Push the legs firmly into the soil.
As stems grow, guide them through the support's grids. Several stems can go through one grid.