Peony Garden FAQs

We do not cut our peony flowers for sale. This is a living museum exhibit of historic and rare peonies that is open for all to enjoy. Cut peonies may be ordered through your local florist and some commercial peony vendors.

The peony garden at the Nichols Arboretum has never been routinely – if ever – fertilized since at least the 1930s – nearly a century ago!

Because of the viral and genetic research being done in the Peony Garden, we do not use any kind of chemicals that could impact the results of the study- including fertilizers and pesticides. Learn more about the research taking place in the garden.

For information on basic peony care, visit the American Peony Society website here.

Tree peonies have woody stems that stay above ground all year. Their leaves are deciduous and drop every fall.

Herbaceous peonies are the most common type of garden peony and make up the majority of the Peony Garden. Each winter, their stems die back to the ground. New shoots emerge in spring from eyes on the roots.

Intersectional, or Itoh, peonies are a hybrid cross between tree and herbaceous peonies. The flowers are similar to tree peonies, but like herbaceous peonies, the stems die back to the ground each winter.

Dr. Hong De-Yuan lists 48 different peony species (33 species and 15 subspecies) in his book Peonies of the World Taxonomy and Phytogeography, published in 2010. These wild peonies are mainly found in Asia and Europe. There are two summer-dormant species native to arid parts of western North America.

The American Peony society lists just over 7,000 different cultivars in their registry. This includes herbaceous, Itoh, and tree peonies. The Peony Garden is currently home to 365 known herbaceous cultivars, 37 herbaceous peonies whose IDs are unknown, 132 known tree peony cultivars, 21 unknown tree peony cultivars, and 38 Itoh hybrids.

For more information about peony species, visit the American Peony Society website. The American Peony Society’s cultivar registry can be found here.

Peonies can be propagated two ways by the home gardener: via division or seed. Peonies are pollinated the same way many flowers are – insect pollinators carry pollen from one plant to another. Fertilized seeds drop to the ground in the fall, lying dormant during the winter, and germinating in spring. Due to the genetic recombination that occurs with pollination (random selection of genes from each parent), peonies grown from seed often do not fully resemble the parent plants. 

Some peonies cannot reproduce by seed and rely on humans to divide and propagate them. These include some hybrid peonies that are sterile and some of the full double peonies, whose stamens and carpels (the reproductive organs of a flower) have become petals.

A cultivar is a breed of peony whose parents are of the same species. Most of the herbaceous peonies in markets today are cultivars of the Paeonia lactiflora species. Hybrid peonies are peonies whose parents are of different species. Check out the American Peony Society’s guide to peony species here! The reproductive process is the same for cultivars and hybrids. Pollen from the anthers of one plant is carefully transferred to the stigma of another.  Due to genetic recombination (the random selection of genes from each parent), the offspring will be genetically different from both parents, resulting in a peony that looks different from its parents and a new cultivar.

In order to see if a new cultivar or hybrid is commercially and biologically viable, peony breeders must often wait several years for their new peonies to bloom reliably. If it is established that the new peony has favorable traits and can be propagated through division, the new cultivar can be registered with the American Peony Society. Curious about the registration process? Check out an overview of cultivar registration here!

The presence and strength of fragrance is all down to genetics. In the early days of peony breeding in both Asia and Europe, fragrance was an important feature. As peony breeding began to track features that would promote sales to the average gardener, breeders began to focus more on colors, forms, and growth habits than fragrance. Many older varieties still have strong fragrances, while some newer cultivars have no fragrance at all. Some have even been reported to have a rather unpleasant scent! To learn more about peonies and their fragrance, visit the American Peony Society website here.

Generally, peonies should be divided every 3-5 years to keep them looking fresh and healthy. Studies have shown that when a peony is divided, its viral defenses are renewed and the plant is less likely to show symptoms of disease. Because there is currently research on peony viruses being done in the Peony Garden, we generally do not divide our peonies. This allows researchers to observe the effects of disease that can’t be seen on commercial peonies, since these are regularly divided. Read more about the research being done in the Peony Garden. 

If you would like to divide your peonies, you can find a guide here on the American Peony Society website.

The Peony Garden is cared for by a team that includes horticulture technicians, interns, and volunteers. The Peony Garden is a large collection and caring for it would not be possible without the generosity of our sponsors and the dedication of our wonderful volunteers! Interested in how you can help? Visit our website here to explore how you can get involved in the Peony Garden!

Our peonies have come from a variety of sources over the years. The original collection was donated by W.E. Upjohn in 1922. Through the following 100 years, the collection has been expanded through donations from private collections and purchases from reputable peony suppliers. Check out the American Peony Society’s list of peony vendors to find a supplier near you!

There are a number of peony societies world-wide. Check out the American Peony Society website to find a society near you!