In Spring, Fragrant Solomon’s Seal Has Delicate White Flowers Suspended from Arching Stems

By Corinne Kennedy

Fragrant Solomon’s seal, in Area ZZW of the Seattle Japanese Garden. (photo: Aleks Monk)

Solomon’s seal is the common name for about 60 species of woodland perennials in the genus Polygonatum. They’re lovely herbaceous (non-woody) plants, with dainty white spring flowers suspended from upright or arching stems. With roots and unbranched shoots that grow from specialized underground stems (rhizomes), they’re classified as rhizomatous. In the southwestern area of the Seattle Japanese Garden, clumps are dotted along the west-side fence.

Our Garden’s plants are native to temperate areas of Europe and Asia, including Japan. Records list the botanical name Polygonatum japonicum (amadokoro in Japanese), but according to taxonomists the correct name is probably Polygonatum odoratum var. pluriflorum. (Even more confusing, many other names are listed as synonyms—including P. odoratum var. thunbergii and P. falcatum). Wild habitats include wet grassy areas, woodlands, and shaded slopes.

The word Polygonatum derives from the Greek poly (meaning “many”) and gonu (meaning “knee joints”), and refers to the many jointed rhizomes of this genus. Our plant’s specific epithet odoratus is Latin for “sweet-smelling,” a reference to its lightly fragrant flowers—and to its popular common name, fragrant Solomon’s seal. The variety name pluriflorum (meaning “several flowers”) further indicates that flowers are generally held in clusters of two or more. The Garden’s plant is one of the few species commonly grown as ornamentals. It’s also known as Japanese Solomon’s seal and common Solomon’s seal. [False Solomon’s seal, the Pacific Northwest native Maianthemum racemosum (aka Smilacina racemosa) is an entirely different plant!]

The meaning of “Solomon’s seal” is ambiguous. It’s thought to refer to the round, flat leaf stalk scars on the plants’ rhizomes, believed to resemble the ancient seal of King Solomon. Alternatively, it may refer to plants’ long history of medicinal uses—notably in China, Korea and Japan—including the sealing of wounds. Rhizomes and shoots were also dried, ground, baked, boiled and pickled to prepare safe and nutritious foods, neutralizing the harmful phytochemicals that can cause digestive distress.

Fragrant Solomon’s seal emerges in spring with red-tinged stems arising singly from the rhizomes. These stems are unbranched, arching, and about 18-24 inches long. Leaves are held alternately on the stems. Medium green and about four inches long, they’re oval-shaped and pointed at their tips. In autumn, leaves and stems turn a pleasing pale yellow or tan before dropping to the ground.

The dainty spring flowers of fragrant Solomon’s seal. (photo: Aleks Monk)

Dainty tubular or bell-shaped flowers, usually in clusters of two or more, open in mid-spring. Suspended from the arching stems, they’re greenish-white, tipped in green, and about 7/8 inch long. They have a light, lily-like fragrance, and persist for several weeks—but unfortunately, they’re partially hidden by the leaves. Plants are self-fertile, and are pollinated by bees. Autumn brings round, pendulous, blue-black fruits. Though only about ¼ inch wide, they’re attractive to birds.

Maturing plants produce more and larger stems each year, as the rhizomes continue to grow and branch. Thick, white and irregular in shape, they develop round, flat scars where the previous year’s stems emerged. Plants are slow to establish but long-lived, and rhizomes eventually become quite large and woody. As seen in our Garden, plants spread to form clusters or colonies, but are not considered invasive.

Fragrant Solomon’s seal is reliably hardy to USDA Zone 4 (minimum temperature -30 to -20 degrees Fahrenheit), and is easily grown in cool-summer regions such as the Pacific Northwest. It does best in part to full shade—and rich, moist, organic, well-drained soils that are mulched with compost or fallen leaves.

Fragrant Solomon’s seal is surprisingly adaptable, especially in our region. Plants tolerate a wide range of soils—from acidic to alkaline, and from sandy to clay. They perform well in morning or dappled sun, and with enough watering will adapt to full sun. Mature plants are considered drought tolerant here, and under shady conditions will tolerate considerable root competition. They are rabbit and deer resistant, and have no serious disease or insect problems, but slugs are attracted to the young shoots.

From a design perspective, the partially hidden flowers of fragrant Solomon’s seal are less important than its graceful arching stems and architectural habit. And one variegated cultivar, P. odoratum var. pluriflorum ‘Variegatum,’ is also recommended for its foliage—attractive green leaves, edged in white, that brighten up shady areas. (Readers interested in this plant will find more information at greatplantpicks.org, a comprehensive website of plants recommended by regional experts.)

Like other Polygonatum species, fragrant Solomon’s seal combines well with other shade-loving perennials—including ferns, hostas, bleeding hearts, and astilbes—and provides a bold contrast to lower, mound-shaped plants. Its value lasts into fall, when plants develop their soft, subtle, autumnal coloring. Theirs is a gentle transition into winter’s darkness, so unlike the fiery displays of Japanese maples.

Corinne Kennedy is a Garden Guide, frequent contributor to the Seattle Japanese Garden blog, and retired garden designer.