Peonies (Paeonia spp.) are one of the longest-cultivated ornamental perennials, first becoming popular during the Sui and Tang dynasties in China. Peony blossoms are full, fragrant and commonly pink, red, white or yellow, although they may come in any color but blue. The plants grow well in U.S. Department of Agriculture plant hardiness zones 3 to 8. With proper care, peonies can live 40 to 100 years.
Peonies can be divided into two types: herbaceous or garden peonies (Paeonia lactiflora) and tree peonies (Paeonia suffruticosa). Intersectional peony hybrids, or Itoh varieties, are crosses of herbaceous and tree peonies. Garden peonies grow to heights between 2 and 3 feet, whereas Itoh and tree varieties are taller, reaching 3 1/2 to 4 feet. Peonies are further distinguished by their bloom type, which may result in single, semidouble, double, Japanese or anemonelike flowers.
Site selection is essential for a peony to thrive. Choose a location that receives full sun and is sheltered from wind. Although peonies prefer loamy earth, they tolerate most soil types, but ensure the ground drains well. Adding organic matter like compost improves drainage. Before planting, test the soil to check that pH levels are between 6.5 and 7.5. New peonies can be planted from April through June, depending on how quickly the weather warms up. Peonies require regular watering and can be fertilized with a low-nitrogen boost in spring when leaves first appear and again after the blooms have faded for the season.
Taller peonies often need structural support to help hold their large blooms upright. During the flowering season, regularly remove spent blossoms. This encourages leaf production and increased flower numbers the following year. If you cut flowers for bouquets, do not to remove more than half the peonies from an individual plant. Excessive flower removal can result in decreased bloom production in the future. In autumn, cut back herbaceous varieties, leaving 3 inches of stem above ground; tree peonies are best left untouched.
Peonies can suffer from several types of fungal infections, including Botrytis blight, verticillium wilt and leaf blotch. Fungal problems are more prevalent during cold, damp weather. Treat infections by removing and destroying any diseased foliage and then cutting stems to the ground after a hard frost. Ants are commonly found on peony buds, but they should not be removed. Ants eat peony nectar and simultaneously keep harmful insect pests at bay. If peonies fail to flower, consider whether they are receiving sufficient sunlight. Other possible causes include excessive nitrogen and inadequate supplies of phosphorus or potassium.
Hundreds of peony varieties exist, so selection can be overwhelming. Consider your local climate and bloom preference. Varieties like the Itoh hybrids “Bartzella” and “Pink Double Dandy” grow best in cooler regions, whereas the herbaceous “Blaze,” “Festiva Maxima” and “Sarah Bernhardt” all can thrive in either warm or cool climates. For maximum flower power, the garden peony “Kansas” has an extended blooming period through summer, or for pure blossom size, consider one of the tree varieties, such as “Glory of Shanghai,” “Robert Fortune” and “Thunderbolt.”
- Sunset: How to Grow Peonies
- The Old Farmer's Almanac: Peonies
- North Carolina State University: Peonies for the Home Landscape
- Organic Gardening: Growing Peonies
- National Gardening Association: Peony Care
- University of California Sonoma County Master Gardeners: Peonies
- Fine Gardening: Paeonia Lactiflora (Common Garden Peony)
- Sunset: 20 Gorgeous Peonies
- University of Vermont Extension System: Tree Peonies
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