The American Peony Society has over 6500 cultivars in their registry. Within all this variety, there are three common types of peonies: tree peonies, herbaceous peonies and Itoh peonies. Here’s a comparison:

‘Hephestos’. TREE PEONIES (Paeonia suffruticosa) Zones: 4-9 Bloom time: April-May Exposure: Light shade during the heat of midday Planting depth: 4 to 6 inches below ground level Fast Facts: Woody shrubs native to China Stems stay above ground all year Enormous flowers (up to 7 or even 10 inches across) Handsome foliage — deep green in summer, bronze and purple in autumn Don’t like to be moved A mature plant can be 4 to 7 feet tall and 4 to 5 feet wide Grow about 6 inches per year

‘Pink Hawaiian Coral’. HERBACEOUS PEONIES Zones: 2-8 Bloom time: May-June Exposure: 5-6 hours of full sun per day Planting depth: ½” in warm zones; 2” in cool zones Fast Facts: Can flourish and flower in the same spot for 50 years or more Stems die back to the ground each winter and reemerge in spring Low maintenance Require little water Naturally resist most pests Aren’t bothered by deer 30+ species including Paeonia officinalis and Paeonia lactiflora Need little fertilizer when grown in rich soil Require good drainage

‘Garden Treasure’ ITOH OR INTERSECTIONAL PEONIES Zones: 4-9 Bloom time: June Exposure: 5-6 hours of full sun per day Planting depth: ½” in warm zones, 1 ½” in cooler zones Fast Facts: Hybrid plants that blend the perennial habit of herbaceous peonies with the sturdiness, giant flowers, and color range of tree peonies Herbaceous in nature, dying back to the ground when winter comes Attractive foliage through summer and into fall Good at the front of the border because they are shorter than tree and herbaceous peonies Showy and don’t need staking

Climate considerations

Your climate may dictate which type of peony you should grow. Use the following information to determine which peonies will grow best in your garden.

• Herbaceous peonies need a certain amount of cold weather to flower. Southern gardeners should favor early bloomers.
• Tree peonies don’t demand below-freezing temperatures, but do require a dormancy period. In regions where winter is a nonevent, dormancy can be forced by trimming off the leaves.
• Intersectional peonies, which die back to the ground when winter comes, can be hardier than tree peonies and are more tolerant of heat and humidity.

Which type of peony blooms the longest?

If you're looking for an extended bloom season, Intersectional peonies can produce flowers for a period of 3 to 4 weeks, with as many as 30 to 50 blossoms per plant. The blooms of a tree peony, if protected from the hot afternoon sun, can last as long as 14 days. Herbaceous peonies bloom for an average of 7-10 days depending on the cultivar.

Flower forms

Peonies are further classified by their flower form. Some types of peonies have a single ring of petals, while other types have multiple rows of petals. Here is a list of the different types of flower forms:

• Single
• Japanese
• Anemone
• Semi-double
• Full double
• Bombs

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