Peonies are one of those spring time perennial flowers that are an old time favorite. These flowers are often fragrant, make for great cut flowers, and come back year after year. They come in many colors including cream, coral, crimson, pink, purple, rose, scarlet, black, white, and yellow. Peonies generally grow two to four feet in height, thriving in full sun and well-drained soil. Their sumptuous blooms will be coming to us shortly in the months of May and June.
The two types of peonies generally grown are the garden peony or Paeonia hybrids and Paeonia suffruticosa, better known as the tree peony. The main difference you will notice between the two is that the garden peony will generally die back to the ground over winter, while the tree peony will retain woody growth through the cold months. Garden peonies are herbaceous perennials that are generally grouped into five categories based on their flower shape: single, semidouble, double, Japanese, and anemone. The tree peonies produce large numbers of flowers on the comparatively taller shrub-like plant. Peonies do well in cooler environments and are suitable to the Kentucky climate. Older peony varieties do best further south because newer varieties require a certain number of chilling hours each winter.
As peonies are coming up this spring and shoots get to about three to four inches in size, one may apply a complete fertilizer such as 5-10-5 or 10-10-10, or organic fertilizer such as 5-5-5, at the rate of 3 to 4 pounds per 100 square feet of bed area. A single application of fertilizer each year is generally adequate to maintain good plant growth and flowering throughout the season. Peonies multiply through tuber growth, which means that the plant will require occasional dividing. This division allows easy propagation to share with friends and family. Once a clump has become crowded, division of the peony is recommended. To do this, dig and separate the tubers being sure each one has three to five eyes. Remove any damaged tubers, or those showing signs of disease. In general, peonies usually do not need to be divided for 10 to 15 years. If you find your peonies or other perennials in need of division, fall is a great time to perform this task.
If you are looking to plant peonies for the first time this spring, you may find them in nurseries sold as potted plants. Otherwise, tubers are generally planted in the fall. When planting garden peony tubers, select a site in full to part sun where peonies have not been planted before. Set the tuber so that the eyes are one to two inches below the soil’s surface. For tree peony tubers, they should be planted so that the soil is covering the graft union, generally four to five inches. After planting, make sure to water the tubers well. When planting in the fall it is best to mulch with two to three inches of straw, wood chips, or leaves. This layer of mulch can help to insulate your new planting over winter while adding organic matter.
For more information on peonies and their availability, visit your local nursery.
Submitted by Tracey Parriman, Agent for Horticulture, Mason Co. Cooperative Extension Service