Peonies are known for their fantastically showy flowers. Thanks to centuries of cultivation and legions of devoted gardeners, an enormous array of peony flowers, forms, and fragrances exists. The species encompasses three different types: herbaceous, tree and intersectional. Each of these has different characteristics. One of these variable traits is height.
Herbaceous peonies tend to reach a height between 2 and 3 feet that usually easily predicted within a variety. As a general rule, the shorter the variety, the lower maintenance and support the plant needs. The herbaceous peony’s heavy blossoms and relatively weak stems usually require that this type of peony be staked.
Tree peonies reach maturity in 10 to 15 years and can be between 3 and 7 feet tall, although most specimens maintain a height under 5 feet. The plant has more growth potential in milder climates where peonies suffer less winter die back. Dwarf tree peonies usually reach a maximum height of 3 feet, medium grow to 5 feet and tall can reach 7. There are several varieties of each.
Most intersectional peonies (also known as Itoh Hybrids) reach about 3 feet in height. This relatively new hybrid of tree and herbaceous peonies is more disease resistant than either the tree or herbaceous type, has a stronger stem than the herbaceous and produces flowers in colors not found in herbaceous peonies