It was with dismay that I discovered there was ragweed growing in our front lawn. None of the plants were particularly large but, unfortunately, some had begun to flower. Ragweed pollen is a primary cause of allergic rhinitis, AKA hay fever in late summer and fall for many Midwesterners. While I am not allergic to ragweed, Kat is and, therefore, I have a particular anathema for ragweed.
There are three species of ragweed native to Minnesota. Ragweed can be found growing everywhere in the Twin Cities, including along the medians and shoulders of freeways and highways. Because of its widespread prevalence, there is no chance of eradicating it. I just do my small part by removing it from our yard whenever I discover it.
The following are photographs of Common Ragweed (Ambrosia artemisiifolia) taken by Katy Chayka of Minnesota Wildflowers.
A point I would like to clear up is that goldenrod does not cause hay fever. Goldenrod and ragweed are completely different species. Both are native to Minnesota, are widespread, bloom in late summer and fall, and grow near each other.
Goldenrod pollen is spread via pollinating insects whereas ragweed is dispersed via the wind. One clue that indicates goldenrod relies on insects for pollination is that its flowers are bright yellow. Ragweed flowers, not needing pollinating insects, are hardly noticeable. As such, whereas there may not be much goldenrod pollen floating in the air, ragweed needs to release a lot of pollen into the air. It is all the ragweed pollen floating in the air that triggers allergic rhinitis in so many people.
While goldenrod can be a nuisance because it can crowd out other species, I much prefer the fields of goldenrod growing in our yard to the stands of ragweed along the highway.