For best results when planting peony seeds, start the seeds indoors in fall, using a humid greenhouse environment, and transfer them to a sheltered location outdoors in the spring. Keep in mind that growing peonies from seed will result in unique cultivars with blooms that look different from those of the parent plant. Peonies typically take a few years to begin producing flowers after they are transplanted outdoors.
To obtain peony seeds for planting, first collect seed buds from peony plants whose flowers have already wilted and fallen from the stem. Put the buds in a cool place such as a garage, placed within an open paper bag, for several weeks. As seeds begin to ripen, the seed pods will crack open. When the buds have fully dried and shriveled up, the seeds can be removed.
Several peony seeds can be planted together in a small container with potting mix. Place the peony seeds up to 1 inch (2.5 cm) deep in the soil, with up to 2 inches (5 cm) of space between seeds. Water the seeds thoroughly, then let the water drain.
A makeshift greenhouse environment can be formed for the peony seeds by placing the entire container into a closed plastic bag for approximately three months in a warm but not sunny indoor area. This humid growing period will give the peonies time to form roots. After roots of at least 1 inch (2.5 cm) have appeared, move the container, still in its bag, into an outdoor location that is about 40 degrees F (4.4 degrees C).
Once a shoot appears, or after about three months, the container of peonies can be removed from the plastic and the individual peonies can be planted outdoors in a sheltered area. Be sure to disturb the root systems as little as possible during transplanting. Growth during this initial season will be slight.
In autumn, provide mulch for the peonies to protect the plants during the winter season. The plants will re-emerge in spring. It is normal for new peony plants to take one or two years to begin displaying blooms, and some specimens could take up to five years to flower.
Peonies are perennial flowering plants, most types of which can grow to be up to 5 feet (1.5 m) in height. Their yellow, white, or red blooms appear in the latter part of the springtime and might be fragrant, depending on the cultivar. Peonies are usually herbaceous, dying in the winter and reappearing in springtime, but some forms of tree peonies retain woodlike stems after losing their leaves. Intersectional varieties feature large flowers similar to those of tree peonies, but their winter behavior appears herbaceous.