If Planting Peonies, Now's the Time
by Jeanne Rose, UC Master Gardener

Are you looking for a perennial plant that will live indefinitely? Have you considered peonies, but heard that they won't grow here? Well, believe it or not, peonies have been recorded as living well over 100 years, and they will grow here!

Peonies begin growth early in the spring, flower in mid- to late spring, and form a rounded three-foot shrub covered with glossy leaves that provide striking texture in your garden until fall. Gorgeous blooms are classified as single, Japanese, anemone, semi-double, crown, bomb, semi-rose and rose. They make excellent cut flowers and wonderful material for potpourri. Colors range from pure white to cream and pink to red. Some of the newest cultivars include deeper reds, chocolate tones, and even pure yellow.

The heavy blooms range from 5-12 inches in size, requiring some means of support. The method that has worked best for me is to cut the lower rings off tall tomato cages, leaving the top three rings with legs. Any support is best placed over the peonies early in the growing season, since peonies grow very rapidly making it more difficult to add later.

The largest blooms may be attained by removing all but the terminal (end) bud on each stem and removing all but 4 or 5 shoots when they reach 4-6 inches in height, but this shortens the bloom period. By leaving all buds and snipping out the central flower as soon as it fades, the bloom season will be longer.

Herbaceous peonies require a sunny location, good drainage, reasonably good soil, and approximately the same chilling requirements as deciduous fruit trees. Chilling hours affect number of blooms. For example, I noticed that there were considerably fewer blooms in 1998 because of El Niño's warmer-than-usual winter temperatures, but in 1999 La Niña brought us some good winter chill and peony blooms were abundant.

Peonies should be planted from fleshy roots in September or October. Ideally the ground should be deeply dug or tilled and a 2- to 4-inch layer of organic matter incorporated, but my peonies were planted with no special soil preparation and they are thriving. Planting holes should be twice as wide as the root system and 3 - 4 feet apart. Plant with the pink growth buds (eyes) one inch or less below the soil surface. Deeper planting may prevent blooms. Once planted, peonies should be transplanted only when absolutely necessary; divisions should be made at the same time.

Peonies do well with regular applications of 5-10-5 fertilizer, although mine have thrived without it. Over-fertilization is more problematic than under-fertilization, especially while plants are getting established. If using manure, make sure to use only well-rotted manure worked shallowly into the soil. Peonies prefer regular irrigation but don't tolerate standing water. My watering method is to flood irrigate the bed approximately once a week during the growing season.

Pests and diseases rarely occur in well-kept peony plants and when they do are seldom serious. There has never been a need for any type of pesticide in the ten or more years I have grown peonies in my garden.

Start looking now for sources of herbaceous peonies to plant this fall. Mail-order catalogs usually list a few cultivars, while specialized peony nursery catalogs list a much broader variety. Prices can vary considerably between vendors. Local nurseries and garden centers are starting to carry a wider variety of peonies, too. Sometimes peonies are prepackaged in convenient boxes.

Give peonies a try, you won't be disappointed.

September 5, 2002