Plant Notes: Syringa

Collected by the waters of Clark's River in 1806, Syringa (Philadelphus lewisii), was named for Merriweather Lewis by Frederik Pursh, the botanist commissioned to catalog the plant specimens collected by the Lewis and Clark Expedition. Native from southern British Columbia to the central California Sierras, then east to Idaho and Montana, Syringa blossoms were incorporated into the Idaho state seal, designed in 1890. In 1931 it was officially designated Idaho's state flower.

A loosely-branched, deciduous shrub, Syringa makes a breathtaking display when in full bloom, usually from May to July. One-two-inch, waxy white, four-petaled flowers appear in clusters of 3-15. Flower centers sport an abundance of yellow stamens and are highly fragrant, resembling orange blossoms – hence the common name Mock Orange. To enjoy the fragrance on a warm day, plant near a patio or walkway, or create a hedge or screen with dramatic effect.

The common name “Syringa” is actually the genus name for lilac, which is botanically unrelated. The upright shrub structure and the abundant bloom are somewhat reminiscent of lilacs, but the two plants are in different plant families.

Syringa prefers full to partial sun; it is drought-tolerant and not picky about soil, growing from rocky ledges to stream banks. In the garden, it responds well to pruning. Cutting out older wood and pruning back taller stems will encourage more abundant flowering. Syringa is top-killed by fire but re-establishes from root crowns and underground rhizomes.

This 3-10 foot tall shrub is characterized by long stems, red when new, fading to gray with shedding bark. Leaves are oval with smooth or lightly serrated edges, arranged oppositely on the stem. The leaves and bark are rich in saponins which yields a mild, soapy cleanser when crushed with water.

New Syringa shoots are browsed by deer and elk. The fragrant flowers attract a variety of pollinating insects and seeds become food for game birds and squirrels. The shrubby habitat shelters birds and small mammals.

Native people made good use of Syringa. Stems were fashioned into finely coiled baskets. Wood was used for cradle hoops, snowshoes, arrows, and fish spears. Removing the pithy center of straight twigs created tobacco pipes.