When I was a kid my father told me that once the goldenrod bloomed summer was over. I always associated goldenrod with the start of school. In general this is true, but the genus Solidago has over a hundred species and one found here blooms in spring. It is a threatened species and rarely noticed.
Most goldenrods are upright perennial shrubs with 2-4 inch narrow tooth edged leaves that emerge from the stem singly. Yellow (rarely white) flowers grow from the stem tips. Some goldenrods can be six feet tall or more and stem hairiness varies from nearly smooth to quite hirsute. Different species interbreed readily, so precise identification is difficult.
One of the more common ones is the Canada goldenrod, a primary food for migrating Monarch butterflies. Young larvae usually eat milkweed. Canada goldenrod tolerates varied fertility and moisture conditions, meaning you can expect to see it anywhere except highly shaded areas. It is a prolific seed producer and it forms a dense mat of roots and rhizomes, also great reasons for its abundance throughout North America.
Many other butterflies flock to goldenrod, not just Monarchs. Because of this there is interest in developing compact ornamental varieties. Fewer fall-blooming plants frequent fields and roadsides, meaning less food is available for bees and butterflies. Goldenrod is easy to grow and presents few challenges for gardeners with purple thumbs.
The only real insect pest to goldenrod is the goldenrod gall. Depending upon how you look at it, it might even have positive qualities. The insect lays eggs in the stems and in response to the invasion the plant forms a barrier of tissue that eventually looks like a golf ball on a stick. When these stems with galls on them are dried they are quite decorative and useful in dried floral arrangements.
Those with pollen allergies sometimes inaccurately accuse goldenrod for their discomfort. However, its pollen is heavy, sticky and not readily spread by wind. Ragweed is usually the culprit. The two grow and bloom in similar locations, but ragweed doesn’t have showy flowers and often escapes accusation. Goldenrod allergies exist, but they are not caused by pollen.
Goldenrod is often recommended by herbalists to treat many problems. Teas and extracts made from leaves and flowers are used to fight inflammation of arthritis and gout. Treatment of colds, flu, sore throat, urinary tract infections and kidney stones are other uses. Some apply solutions topically to treat eczema and minor wounds.
Goldenrod contains many diuretic chemicals. Therefore, people who are already taking medicine to remove excess water might want to consult their doctors before consuming too much of it. The same goes for those taking Lithium. It could build up in their blood to potentially dangerous levels if too much body fluid is removed. Other than that, there are few concerns regarding goldenrod use.
Tea flavor varies among species. Some types, most notably sweet goldenrod, have anise scented and flavored leaves. The licorice flavor is quite pleasing to me, but that species isn’t abundant here.
Ted Manzer teaches agriculture at Northeastern High School.