Peonies are the traditional flower for Memorial Day. In the 1800s, when the holiday was called Decoration Day, peonies were one of the few flowers in bloom in late May and were widely used to adorn the graves of fallen soldiers.
Their huge, lavish blooms continue to make them one of America’s most treasured garden flowers, says University of Missouri Extension horticulturist David Trinklein.
Peony is the common name for plants in the genus Paeonia. Its name comes from Paeon, who was a student of Asclepius, the Greek god of medicine and healing. According to myth, Asclepius became jealous of Paeon and threatened to kill him. Zeus rescued Paeon by turning him into a flower.
Most peonies planted today are hybrids native to Asia, southern Europe and western North America. Garden peonies grow as bushy herbaceous perennial plants. They grow up to 3 feet in height. Their deeply lobed leaves and extravagant, delightfully fragrant flowers fan out up to 6 inches in diameter. They come in a myriad of colors.
Peonies need plenty of room because of their size. Plant them 3-4 feet apart in a fertile garden loam and full sun exposure.
Because peonies tend to be long-lived, good soil preparation before planting is vital. Incorporate well-decomposed organic matter 10 to 12 inches deep in the general area and make individual holes wide enough to spread roots well. Add a modest amount of fertilizer high in phosphorus (such as 5-10-5 or bone meal) and mix well into the soil.
Trinklein said shallow planting works best for peonies. Reduced or inhibited flowering happens when growing points of the crown are set more than 2 inches below the soil’s surface.
When undisturbed, peonies often persist in flowering well for 20 years or more. Divide if growth is poor and plants fail to bloom after years of performing well, Trinklein said.
Fertilize peonies sparingly. Excessive fertilizer, especially nitrogen, leads to poor flowering. If top growth slows and plant vigor declines, apply several tablespoons of a complete fertilizer high in phosphorus and potassium (such as 6-24-24) about 6-18 inches away from the crown. Fall application is preferred, although early spring is satisfactory.
Peonies are relatively pest-free and rarely require pesticides.
In a classic case of “guilt by association,” some people believe that ants are necessary for peony flowers to open. Peony buds draw ants because of the sweet exudates of the buds. But ants do not help or hinder the flower in any way, Trinklein said.
Missouri Environment & Garden, a newsletter from MU’s Integrated Pest Management program, has more on peonies:
-ipm.missouri.edu/MEG/2017/9/peonies(opens in new window).
-ipm.missouri.edu/MEG/2018/5/antsOnPeonies(opens in new window).
– Linda Geist