New gardeners or people moving into a new garden may have trouble identifying their plants. Peonies are such old garden stand bys that they are frequently found in old gardens. But what KIND of peonies are they?
 
There are four basic kinds of peonies:

• 1. Herbaceous or Garden Peonies  These are the most common type of peony found in gardens world wide. They have been cultivated for centuries and are favorite 'Pass Along' plants.  As the name says, these plants are herbaceous, that is, the stems last for only a single growing season and die to the ground each winter.

• 2. Tree or Woody Peonies  These are more accurately called 'Shrub' Peonies because most of them stay under six feet tall and they all have woody stems that do not die to the ground like Herbaceous types. Since propagation is a bit more difficult they are not commonly passed along and are uncommon in many gardens, even today.

• 3. American species of interest to scientist mostly. This is one or two wild  peonies native to the Pacific coast to British Columbia. The flowers are small, brown and deep within the foliage. Many gardeners would not recognize these as any kind of peonies. And they are difficult to grow outside of their native habitats. No further characters given.

• 4.  Intersectional or Itoh Peonies These are deliberate and difficult crosses between the first two types of peonies. They are rare and expensive so it is unlikely they will be found in old gardens. They combine the features of both types with stems and growth habits of herbaceous peonies, but foliage and flowers more like tree peonies. No further characters given.

• 1. Stems - Garden peonies have stems that die to the ground each fall. They are not woody. They arise directly from the ground level and die back to ground level in winter.

• 2. Bloom Season - Most garden peonies bloom in May in middle zones such as Kansas City to the mid-Atlantic states. Most gardeners know of 'Peony Season' and you can see many plants growing in areas where these peonies thrive. 3. Color - Most garden peonies are red (reddish purple actually), pink or white. Most garden peonies have been selected for flower form (double or full flowers) and size (many over 6 inches in diameter) and come in a limited range of colors and shade (compared to tree peonies)

• 4. Size - Garden peonies are rarely over 30 - 36 inches tall. Most plants are in this range, but a few selected varieties can be over 4 ft and some under two feet.

•  5. Foliage - Leaves on herbaceous peonies are often thick and waxy. Leaves are often divided into three x three leaflets, but leaves lower on the stem and at each flower may be single.

• 1. Stem. - Woody peonies have woody stems that get bigger and bigger each year. They do not die to the ground each year. Buds up on the stems develop and grow, extending every stem. Most new growth occurs from stem buds, but some new stems will form from ground level, too.

• 2. Bloom Season - Most Woody peonies bloom before garden peonies beginning around mid-April in the states mentioned. Woody Peonies are among the earliest of peonies and can bloom very early.

• 3. Color - Tree peonies come in a wider variety of colors including red, white, pink, yellow and mixed shades. Flowers are also much bigger than herbaceous peonies. Peonies have been developed from a wide range of species resulting in charming mixtures of shades from pastel to bright.

• 4. Size - Although called "Tree' Peonies, these are really woody shrubs. Most of them get to 36 inches and slightly taller, most in the 4 to 6 ft range. A few species and selections can grow almost twice this height. The tallest rarely get more than twelve feet tall with age.

• 5. Foliage - Tree Peony leaves are soft and flexible and usually softer green in color compared to herbaceous peonies. Leaves can be divided into 3 x 3 or even more leaflets.