Skip to main content

Goldenrod offers meals for lots of insects

Goldenrod is a plant, native to North America, that grows in reasonably moist open areas in meadows, prairies and roadsides. In most parts of the Eastern U.S. goldenrod plants bloom during the month of September. Thus, goldenrod is blooming when most other species of plants have tucked their blossoms away for the year.

Goldenrod is aptly named because of bright yellow flowers atop upright rigid plant stems. There are over 100 species of goldenrod scientifically classified in the genus Solidago. Some people consider goldenrod a weed. But as is always the case, whether a plant is a weed is in the eyes of the beholder.

Goldenrod has sometimes been perceived by people to be a cause of hay fever. This is unlikely because goldenrod pollen is large and heavy and is not carried by the wind. The plant is insect-pollinated. One of the reasons for the notion about hay fever is probably that ragweed, a wind-pollinated plant, sheds pollen about the same time of the year that goldenrod is in bloom. We all know what happens to hay fever sufferers when ragweed pollen is blowing hither and yon.

Positive aspects of the plant include the fact that young leaves of goldenrod plants are edible. The leaves can be dried to produce a tea, and blossoms make a nice topping for a salad. Practitioners of herbal medicine use it as an antibacterial dressing. Native Americans chewed it to relieve toothache.

The plant also serves as a state symbol. Goldenrod is the state flower in Kentucky and Nebraska, the state wildflower in South Carolina and the state herb of Delaware.

Goldenrod, like most plants, also serves as food for insects. There are around 50 species of insects with immature forms that feed in the stems of goldenrod. Such feeding results in plant growths called galls. Gall-causing insects associated with goldenrod include flies, wasps, moths and midges. Midges are the most common, making up about two-thirds of insects that cause galls in goldenrod.

The other benefit to insects is that they gather pollen and nectar from blooming goldenrod plants. The other day I did a quick survey of the insects crawling on goldenrod blossoms. In a couple of minutes I found several species of flies, three types of beetles, a lot of tiny wasps, a yellow jacket, three honey bees, two bumble bees, a bald-faced hornet, a monarch butterfly, a day-flying moth and a praying mantid. One might say that the goldenrod blossoms were buzzing with activity.

All of the insects were attracted to the yellow blossoms in search of a meal. The beetles were eating pollen, but the others were most likely seeking a sip of nectar. The praying mantid was hanging around, hoping to make a meal out of one of the other insect visitors to the flowers.

That monarch butterfly was on its way to Mexico and was gathering nectar to supply energy for the next phase of the trip. While milkweed plants are essential as food for monarch caterpillars, the availability of nectar-producing plants in the fall are equally important for the migrating butterflies headed south to wintering sites south of the border. A few days earlier we saw monarch butterflies feeding on goldenrod in Cuyahoga Valley National Park in Ohio. Each year the monarchs fly through the park following their trek over Lake Erie as they fly from Canada to Mexico.

Honey bees and bumble bees were collecting nectar to make into honey. In general, fall blossom honey produced by honey bees is dark in color and has a stouter taste than honey made earlier in the season. To me, honey produced when the bees are working goldenrod blossoms has the color and taste similar to molasses.

The day-flying moth on the goldenrod blossom was a Ctenucha moth. This black moth with metallic blue-green body and a yellow-orange head and fuzzy antennae really stood out as it crawled on the yellow goldenrod flower. Just like most of the other insects on the flower, it was looking for pollen or nectar. Goldenrod is certainly a fall "snack shack" for insects!