Plants for Pollinators: Goldenrod

Pollinators are an important part of any landscape, with 90% of flowering plants needing an animal pollinator. Insect pollinators, like honey bees, wild bees, and butterflies have been declining in recent years due to a variety of stresses. Loss of habitat is a major factor in declining honey bee health and declining wild pollinator populations, so planting a variety of flowers that will provide nectar and pollen throughout the growing season is important for their health and conservation. Goldenrods are a great late season pollen and nectar sources for many pollinators and other insects. Goldenrods are a diverse group of plants, with species that grow in many different habitats all over Minnesota. Most prefer sunny areas of meadows and prairies, but some species grow in woodlands or wetlands. The University of Minnesota, Department of Botany described 19 species of goldenrod in 1945, and the Department of Natural Resources says there are at least a dozen species in Minnesota currently. In this presentation, we will focus on Showy goldenrod, or Solidago speciosa. Showy goldenrod has a stout stem, with smooth leaves. It bears a dense pyramidal or club-shaped terminal cluster of small yellow flower heads. Unlike many goldenrods, whose flower clusters tend to droop, the flower clusters of showy goldenrod are erect or upward curving. It’s height ranges from 2 to 7 feet, and it blooms from August to October. Showy goldenrod is tolerant of different growing conditions including wet soils and dry soils, but it does best in average soil moisture conditions with good sun exposure. Its native habitat is the tall grass prairie and open woods. It’s thought that goldenrod causes hay fever but the true culprit is ragweed. Both plants bloom at the same time but ragweed is wind pollinated. Because Goldenrod pollen is too sticky and heavy to be blown far from the flowers, it is mainly pollinated by insects. So, if you don’t appreciate goldenrod for its lovely fall color, you can always make a cup of goldenrod tea, put in some goldenrod honey, and watch the bees... Showy goldenrod blooms late in the growing season, providing pollen and nectar for many insects before the long winter. A 2008 study of bee visitations to native perennials in Michigan found Solidago speciosa to be one of the most attractive late season plants to both wild and honey bees. Some of the more common pollinators are honey bees (Apis mellifera), bumblebees (Bombus species), carpenter bees (Xylocopa species) and sweat bees (Halictidae). The native bee, Andrena placata is a specialist on goldenrods, so goldenrods are essential for its survival. Along with bees showy goldenrod provides nectar for butterflies, and moths and other beneficial insects. Native gardens are a good way to provide habitat and resources to pollinators in your home landscape. Showy goldenrod is one of the last major bloomers in your fall garden. Showy goldenrod works well with other native plants such as brown eyed Susans, Blazing stars, asters and grasses. According to The Minnesota Department of Transportation there is roughly 175,000 acres of green space along roadsides in Minnesota. Through conservation and restoration of prairies along these roadsides we could potentially provide more habitat and resources for pollinators. Due to showy goldenrods ability to adapt to a wide range of growing conditions it could ensure pollinator resources late into the fall in these roadside plantings. Showy goldenrod not only provides resources for pollinators but also attracts predatory insects such as predatory wasps, syrphid flies and goldenrod beetles that will help in biological control. This makes showy goldenrod an ideal plant for conservation planting on farms. The map on the left shows pre-settlement prairie lands in yellow. The right map shows that the prairie has been replaced by cultivated land. We as humans have disrupted our natural habitats, and if we do not learn to share our land with animal pollinators, the ecological stakes will become very high.