May: Paeonia suffruticosa: Elegant, semi-double pink flowers in spring! 

Botanical name – Paeonia suffruticosa  Common name – tree peony. Location – South of the azumaya, in the northwest area of the Garden.   (Photos by Aleks Monk) 

A lovely tree peony with semi-double pink flowers graces the northwest corner of the Seattle Japanese Garden, blooming in late April or May. Botanically, tree peonies are not trees, but rather deciduous shrubs with large, bipinnate (twice-divided) leaves. Unlike the more familiar herbaceous peonies, they form a framework of woody stems, usually to about 5 feet tall. The Garden’s plant was received in 2004 as Paeonia suffruticosa, without a specific cultivar name. 

Paeonia suffruticosa is not native to Japan but was introduced there from China during the Tempyo period (729-749 CE). Since then, Japanese breeding work has focused on improved flower size, color, and form. Yet many of the more than 150 cultivars known in Japan’s Edo period (1603-1868 CE) no longer exist—and by the early 21st century only about 30-40 cultivars were being grown. 

Nonetheless, tree peonies (known as botan) have long been grown as pot plants and in the gardens of Japan, admired for their beauty, resilience, longevity, and use in traditional medicine. Portrayed in poetry and the visual arts, their flowers represent good fortune and nobility of spirit.

In the 19th century, Japanese forms of P. suffruticosa were introduced to the West, where breeding efforts continued. In recent decades, some authorities have argued that the botanical name should be Paeonia x suffruticosa. The added “x” indicates the hybrid nature of these elegant shrubs, whose genetic ancestry is more complex than originally believed. Unfortunately, it’s not known whether the Garden’s plant derives from Japanese or Chinese forms. 

In the wild, tree peony flowers may be red-purple, pink, yellow, or white—usually with a mass of golden stamens in their centers. Our Garden’s plant has elegant semi-double pink blooms that are cupped in form. Their petals—deeper pink inside—have ruffled edges. 

In cool climates like our own, tree peonies grow best in full sun or light shade—and in rich, organic, well-drained soil. Large-flowered cultivars may need to have their flowering stems supported by staking.

This morning the green fists of the peonies are getting ready 
to break my heart 
as the sun rises… 


(from Peonies, by Mary Oliver) 

Sources for information on Paeonia suffruticosa: 

Chie IidaPaeonia suffruticosa, tree peony, April plants