Gardening: Peonies one of the showiest shrubs in the garden

This has been the year for peonies. Mine have been blooming since the first week of May and are just now wrapping up.

Peonies are one of the showiest shrubs in the garden. With colors in every shade but blue, peony flowers create show-stopping blazes of color for about six weeks each spring, depending on the variety. The flowers are prized for bouquets and are especially popular as a wedding flower. On top of their beauty, they are hardy, rarely bothered by insects or diseases and maintain a well-behaved size in the garden.

There are three kinds of peonies: herbaceous, tree and the new intersectional Itoh hybrids which are a cross of the first two. Herbaceous peonies die to the ground in the fall while tree peonies have wood stems and merely shed their leaves. The intersectionals have the neat, compact growth habit of the herbaceous peonies but with shorter and stouter flower stems of the tree peonies which keeps the flowers from drooping in the rain or under sprinklers.

Herbaceous peonies are hardy down to zone 3 and are so tough that one of the newest emerging peony cut flower production areas is around Anchorage and Fairbanks in Alaska. There are currently more than 50 commercial peony growers supplying cut flowers to the worldwide bridal market from June into September, long after the crops in the Lower 48 have finished but before the crops in the Southern Hemisphere are ready.

Peonies need full sun with a little afternoon shade. They need a well-drained soil and benefit from an annual fertilization using a 5-10-10 garden fertilizer. They need an inch of water a week during the growing season and benefit from being mulched with 2 to 3 inches of compost or shredded leaves or pine needles. Keep the mulch away from the stems.

While peonies are easy to grow, they can be a challenge to plant or transplant. Peonies prefer to be transplanted in the fall after their foliage has turned and died back. They can be transplanted in early spring just as growth emerges, but you will sacrifice a year of blooms.

Containerized plants can be planted in the spring if you minimize disturbance to the roots. Just remove the plant from its pot and set it in the hole.

To dig a peony, locate the base of the stems and then insert a shovel about a foot out, working your way around the plant. Gently pry up the root mass and slide it onto a tarp or piece of cardboard to move it to its new home. Dig the new hole twice as wide as the root ball. Place the root ball in the hole so that the plant crown is at the same level it was in its original home. Back fill with a mix of compost and original soil. Water it well. If the growing buds in the crown are buried too deeply, the plant may not flower for several years if at all.

Pat Munts is the co-author, with Susan Mulvihill, of the “Northwest Gardener’s Handbook.” Munts can be reached at pat@inlandnw gardening.com.