About a dozen species of goldenrods bloom in Minnesota between July and October, but the peak of bloom comes in early to mid-September, when a broad band of goldenrod colors is seen across the landscape. A variety of habitats — old fields, prairies, hardwood forests, sandy soil, moist places — are colonized by goldenrods.
Goldenrod flowers are bright yellow and have considerable nectar, so they are visited by many pollinators such as bees, flies, beetles and butterflies. Their pollen, which is sticky and heavier than the typical windblown pollen, is carried by insects from flower to flower. Because little goldenrod pollen gets into the air, these plants are not considered hay-fever plants.
The use of goldenrods as summer and fall flowers in perennial gardens is becoming more popular. Also, some beekeepers locate their hives near fields of goldenrod, as the radiant flowers provide much nectar and remain conspicuous well into the twilight hours.
There are about 85 species of American goldenrods. Kentucky and Nebraska have each designated one as its state flower.
Among the showiest of goldenrods this time of year is the stiff goldenrod, a common perennial of prairies and dry, open thickets. Migrating monarch butterflies, hungry for nectar, are attracted to the dark yellow blossoms. These flat-topped clusters, several inches wide, are also visited by other butterflies, honeybees and wild bees.
Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.