Thom Smith | NatureWatch: Take a closer look at goldenrod galls

Don't miss the big stories. Like us on Facebook.  

Q We live along a dirt road with fields on either side and close to the road. Where the farmer doesn't mow, there is a tall plant that I believe is goldenrod. My question is what are the 1-inch knobs or balls growing on some of the stems? We saw a couple left from last year that are brown and hard. Is it a disease of some kind?

— Reader, North Adams

A You are correct, it is goldenrod and a specific species, the Canada Goldenrod. They are now coming into their full golden color, and few wildflowers are as spectacular. The growths are galls, (I call them "bonkers," because in my earlier days we would "bonk" each other on the head with them.)

Each gall is caused by an insect, the goldenrod fly, that lays its egg in the stem of the plant in the spring when the goldenrod is young and the stem still tender. By fall, the larva is shy a quarter of an inch and, as the chill of winter intensifies, the little grub enters diapause — what we might call suspended animation — for the winter. It is then ready for the cold weather that allows it to convert a form of glucose or sugar into glycerol, which acts as an antifreeze. And in the spring, it pupates — changing into the adult fly. That is if a downy woodpecker or a black-capped chickadee does not peck its way into the gall for a snack.

Find the culprit: Hold the gall firmly on a cutting surface — I use kitchen tongs to hold the gall steady — and with a sharp knife cut the gall parallel to the stem about 1/4 inch and twist the knife to split the gall open. Within you should find a cream-colored larva. Poke around if you don't find the larva at first or try another gall. Sometimes, I have had to cut open three or four before finding one. It will be a plump white or cream larva (or grub), and if you are careful plucking it out with a toothpick, you will be able to examine it.

Those dried leafless brown stems with the "bonkers" should be examined in the spring, probably around May. If successful, the larva will have transformed into a tiny fly and you will see a small hole in the side of the gall. With luck, it will have escaped its winter nursery to mate and deposited the next season's gall.

Article Continues After Advertisement

Be careful of ticks when walking through fields, either now or in the spring, or for that matter any time the temperature is above 40 degrees.

Goldenrods are lovely wildflowers with roughly 25 different kinds, counting varieties in The Berkshires. Few plants are as misunderstood as the goldenrod because it is so eye-catching while the ragweed is more common, but unremarkable, rarely catching a person's attention while sneezing. The truth is, the goldenrods don't contribute to allergies or hay fever, their pollen is heavy and too sticky to be airborne. It is transported from flower to flower by flying insects that visit the flowers to feed. They are important food sources for insects during the late summer and early fall. And the plant is an important part of any pollinator's garden. For several years, a neighbor had a wonderful patch of goldenrod, and I convinced her not to cut it. She respected my suggestion, but apparently this year, her gardener did not.

Article Continues After These Ads

The culprit causing itchy eye and runny nose is ragweed (for the most part), not goldenrod.


Massachusetts Audubon Society suggests action you can take this week to help keep the Endangered Species Act strong.

"Changes to the federal Endangered Species Act have been proposed that would significantly weaken how habitat is protected under the law. You can help by asking your Congressperson to oppose the changes and uphold protections for our most vulnerable species."

Article Continues After Advertisement


I am worn out reading, watching and listening in recent years more, not less, about the degradation of our environment. Ever since our battle to curb acid rain began in haste back in the 1960s, when I recall letter writing, promotions and education that I was involved with, we are learning of softening the laws governing air pollution, the reason behind acid rain. And it is only one of many movements in Washington, D.C., to counter the continuing struggle to improve our environment.     

Remember when the lakes in New York's Adirondacks were turned into pools of low pH water that killed fish, and fish-eating birds like the loons that after all these years are finally coming back, even in the Berkshires.

The problem, that for the most part, affected the eastern states and began in the 1950s with the Midwest power plants spewing of sulfur dioxide and other airborne chemicals turning our puffy white clouds into cargoes of acidic rain.

Then the U.S. Congress imposed acid emission regulations through the Clean Air Act, eventually reducing sulfate and nitrate in rainfall by about 40 percent. Now, I hear that the federal government is attempting to reduce emission regulations resulting in the effectiveness of the Clean Air Act.


If you'd like to leave a comment (or a tip or a question) about this story with the editors, please email us. We also welcome letters to the editor for publication; you can do that by filling out our letters form and submitting it to the newsroom.

Powered by Creative Circle Media Solutions