How to Plant and Grow Peonies

Peonies are a favorite of many gardeners. Their impressive, long-lasting blooms never fail to delight the senses, whether growing in the garden or displayed in bouquets. Not only are these perennials hardy and tough, but once established, peonies will bloom reliably for 20 years or more. Here are some tips for planting and growing them.

Selection

Peonies bloom in late spring or early summer. By planting a mix of varieties and types, you can extend the blooming period by as much as two or three weeks.

Peonies can be divided into three main groups:

• Paeonia lactiflora includes the Chinese Peony, June Flowering Peony, Double Peony, Garden Peony, and Japanese Peony.

• Paeonia officinalis includes the Early Hybrid Peony, Common Peony, and May Flowering Peony.

• Paeonia tenuifolia includes the Fernleaf Peony.

Double or Chinese peonies are the most popular type of peonies grown. They feature massive fragrant flowers (pink, red, or white) that resemble huge roses. Japanese peonies, a related species, have single flowers with distinctive centers featuring a puff of short, modified petals.

Early hybrid peonies have huge flowers (up to 8 inches across) and bloom a week or two earlier than the Chinese peonies.

Fernleaf peonies are rare and very unique looking. They have deep crimson flower atop fine, fern-like foliage.

Varieties with large, heavy flowers (especially doubles) usually need staking. Support should be in place before the leaves unfurl. Single flower types don't capture and hold as much water and are less prone to flopping over from heavy spring rains.

Planting and Transplanting

When: Autumn is the best time to plant peonies, whether they are newly purchased or simply being moved. Plant them at least six weeks before the ground is expected to freeze in your area. Make sure new plants have plenty of time to make new roots before growth stops for the winter.

Where: Peonies are "long-haul" plants. They perform best after being in the same place for a long period of time. Select a site where they can grow and remain undisturbed for years to come.

Choose a location where peonies will receive at least 6 full hours of sun each day. Shadier locations will result in less blooms and weaker stems. Peonies do not tolerate standing water, so make sure the site provides ample drainage. Space multiple plants at least 36 inches apart.

How: If you're digging up and dividing a clump, start by cutting off and discarding the spent foliage. Dig up the roots carefully and gently remove any loose dirt. Cut the clump into sections, leaving at least three to five eyes and a good portion of root system on each one.

Dig planting holes roughly twice as deep and wide as the peony roots. Prepare the soil by working a little compost, peat moss, or well-rotted manure in with the soil you remove. Add in a handful of bone meal or green sand as a source of potassium to stimulate strong root growth and flower set.

Replace some of this soil mix and set the plant in on top, making sure the budlike eyes are no more than 1 to 2 inches below the ground. Deeper planting will result in failure to bloom.

Back fill gently (don't tamp the soil around the plants). Water in, then top off with additional soil if necessary.

Fertilizing

In the spring (April/May) peonies will appreciate a generous application of compost and a shot of a low nitrogen organic fertilizer (5-10-5 or 5-10-10). Feed them again when their buds reach the size of peas.

Deadheading

To keep peonies looking their best, deadhead individual stems right after blooms fade. This puts the plant's energy back into growing roots and food storage instead of wasting energy on trying to produce seeds.

When cutting flowers for arrangements, leave at least 3 leaves below where the stem is cut to help produce food for development of next year's blooms.

Disbudding

Like many plants, peonies will make larger flowers if forced to make fewer of them. Disbudding is a technique commonly applied to peonies and other flowers which have clusters of buds on each stem. This technique is often used by growers who show peonies in flower exhibitions.

Peonies have several buds, some primary (lead buds) and some secondary (smaller buds branching off from the lead buds). A large number of secondary buds require the plant to put lots of energy into growing a large number of (smaller) flowers. By removing several of the secondary buds, the plant puts the same amount of energy into fewer (bigger) flowers.

Why the Ants?

Have you ever been told that ants are necessary to open peony buds? Not true. Peony buds will open with or without ants, but the two do share a special relationship.

Peonies have tiny, specialized tissues (nectaries) at the edge of their bud scales that secrete nectar. These microscopic nectaries may go unnoticed by humans, but not by ants. This highly nutritious blend of sugars, proteins, and amino acids makes an ideal meal, and is the reason ants are always seen crawling over peony buds.

In exchange for the nectar, ants offer peonies a valuable service-protection. Any bud-eating pests that arrive on the peonies are quickly attacked and discarded.

Fall Care

After the first frost, stems on mature peonies can be cut off at ground level. If there was any sign of leaf spot of other disease problems during the season, the foliage should be placed in the garbage or burned, and not added to the compost pile.

After the ground is frozen 3 or 4 inches down, add a protective layer of mulch to protect plants from frost heave in the winter.