Peony tree, also known as paeony, is a perennial shrub valued for its large, colorful flowers, ease of care and compact growth habit. Despite its name, the plant is actually a shrub, though it can be grown as a small tree. The shrub blooms during May and June, producing flowers in shades of white, pink and red, depending on the variety. Native to temperate regions of Asia, Europe and North America, peony trees thrive in USDA Plant Hardiness Zones 4 to 9 and are commonly grown in border gardens across the United States.
Plant a peony tree in mid-spring in a location that receives partial shade throughout the day and contains moist, fertile, well-drained soil for optimal growth. Space peony trees at least 3 to 4 feet apart to allow enough room for their mature size.
Spread a 2- to 3-inch layer of organic mulch over the soil surrounding peony tree to insulate the soil, deter weeds and increase moisture retention. Start the layer about 3 inches from the base of the tree to allow air circulation. Replenish the mulch as necessary throughout the year to keep it at least 2 inches thick.
Water the plant once every 7 to 10 days to prevent the soil from drying out completely. Apply water during the early morning so excess moisture can evaporate before temperatures drop later in the day. Reduce the frequency of watering to once every two weeks during winter.
Feed peony tree sonce per year during early spring just before new growth begins. Use a low-nitrogen 5-10-10 NPK fertilizer to encourage the plant to focus on root and flower formation. Apply at the rate recommended by the manufacturer for the best results.
Remove peony tree flowers as soon as they fade to prolong the blooming season and encourage the formation of additional flowers. Pinch off the flowers near where they meet the stem to minimize damage and risk of disease.