Ragweed is pollinated by the wind; pollen is small and light and very easily spread by wind. Goldenrod, on the other hand, is pollinated by insects. Its pollen is quite heavy and sticky. It DOESN’T spread in the air.
One reference that I read compares ragweed pollen to a ping pong ball and goldenrod pollen to a giant metal wrecking ball. That’s a good analogy for understanding the movement of ragweed.
So, leave the goldenrod and remove the ragweed.
Speaking of goldenrod, there are hundreds of native species of this plant in the United States. Ohio is home to several of them, and the common or Canada goldenrod (Solidago canadensis) that you see in the fields isn’t one.
If you search for Ohio goldenrod species, you will come across the Ohio Perennial and Biennial Weed Guide which considers Canada goldenrod a weed. And it is if it gets into a farm field or garden.
Goldenrod has an extensive root system that is deep and fibrous. The plant tends to break off at the base if you try to pull it. Digging it or using a pesticide is the best option.
If you have one of the native species, let me know or give it to someone who has a prairie or could use native goldenrods in the landscape. Dusty, false, leafy, stiff, showy, slender showy, sweet and white upland goldenrod are all native to Ohio among others.
I have not seen one of the native species while hiking and paid good money a few years ago to purchase four different species. Don’t tell my husband, he would flip if he knew I paid money for goldenrod!
In addition, there are a few great cultivars on the market that are perfect for home gardens and attract pollinators just like the native species. I have Fireworks, Little Lemon, and Golden Baby.
The cultivars have a little better habit for the home garden. But they aren’t the culprit’s causing ragweed.
Pamela Corle-Bennett is the state master gardener volunteer coordinator and horticulture educator for Ohio State University Extension. Contact her by email at firstname.lastname@example.org.