Peonies (Paeonia spp.) are beloved for their showy, large flowers that are bowl-shaped and colorful. Peonies are long-living perennials that bloom in a wide range of flower colors, including shades of pink, white, yellow and red. There are two main types of peonies, hebaceous (P. officinalis) and bush or tree (P. suffruticosa). Herbaceous peony types are typically grown from tubers and grow 2 to 4 feet tall. In general, herbaceous peonies are also easier to grow than tree types. Herbaceous peonies are categorized into five sub-types according to their flower characteristics, including single, semi-double, double, Japanese and anemone.
Plant the peony tubers in fall. Select a planting site with well-draining soil that doesn’t stay soggy or become waterlogged. Ensure that the location receives at least six to eight hours of full sunlight each day.
Prepare the planting bed by removing all weeds, grasses and other debris. Loosen the soil to a depth of 6 to 12 inches. If your soil isn’t well-draining, mix some peat moss, organic compost or well-rotted manure into the soil--one part for every three parts of native soil.
Dig shallow holes for the peony tubers. Plant the tubers so that the buds, or “eyes,” are 1 to 2 inches beneath the soil surface. The tuber eyes are bright red.
Water the soil deeply and thoroughly. Spread a 2-to-3 inch layer of coarse, organic mulch over the planting bed.
Fertilize the peonies once each year in spring when the shoots are 3 or 4 inches tall with a granular 5-10-5 NPK formula fertilizer. Scatter 3 to 4 lbs. of fertilizer per 100 square feet of planting bed area and water the fertilizer granules into the soil.
Water the peonies deeply to soak the soil down to and around the tubers once each week during summer when rainfall is less than 1 inch.
Cut the peony stems back to about 1 inch above the ground level in late fall or early winter, after the first hard, killing frost. Spread additional mulch over the peonies to protect the tubers from heaving out of the ground during winter during the first one or two years.