With the weather beginning to change, fruiting plants will soon become a rare sight throughout the Forest Preserves of Cook County. However, one plant that may hold onto its fruit into the colder months is nannyberry (Viburnum lentago).

Nannyberry is a common shrub of moist woods and prairies that provides fruit for birds in winter. Its blue-black berries remain on the plant well into winter.

“According to biologist Bernd Heinrich, the fruits are not eaten by fall migrating birds, but rather provide food for our winter resident birds such as blue jays and crows,” explains Forest Preserves ecologist Kristin Pink.

In addition to providing a wintertime food source, nannyberry provides year-round help to insects and wildlife. During spring, the shrub serves as a host plant for spring azure (Celastrina ladon) larvae, which transform into vivid, blue-hued butterflies.

According to the Lady Bird Johnson Wildflower Center, visitors may also notice nannyberry will feature an array of different colors as the seasons change: beautiful, clustered white flowers in spring; dense and dark green leaves in summer; vibrant red leaves in fall; as well as the small, blue-black berries in winter.