Friday, September 9, 2011


It's that time of year again: sneezing, runny nose, watery eyes. Many folks think their symptoms are caused by goldenrod, which are conspicuous along roadsides. Their yellow color fills fence rows, and sometimes spreads across fields. But this pretty wildflower isn't to blame; here's the culprit:
Ragweed is as inconspicuous as goldenrod is visible. You almost have to know what you're looking for to see their small, green flowers. The plants can easily be written off as just a bunch of weeds beside the road, although these Giant Ragweed plants grew to 8 or 10 feet tall in a cluster that ran 60 feet or more along the  roadside.

Goldenrod and ragweed bloom at roughly the same time every year, and much of their ranges overlap. Goldenrod's bright color indicates they are pollinated primarily by insects. Ragweed's green flowers don't attract insects, and they release copious amounts of pollen into the wind. As a general rule-of-thumb, insect-pollinated flowers do not cause nasal allergies, while wind-pollinated species often do. So don't fear the pretty flowers.

There are about 15 species of ragweed in North America and more than 60 species of goldenrod.


  1. My gran used to grow Goldenrod in her garden. I don't think it grows wild here. And thankfully I don't get the sneezes!

  2. That's right both Goldenrod and Morning Glory are grown in English gardens but don't seem to spread into the wild or even become a nuisance in the garden.

  3. It's definitely sneeze season here. Interesting information.

  4. That's interesting. I only know one kind of ragweed here in Britain, it's bright yellow and rather pretty. It's also really poisonous to livestock. But since it is bee pollinated, then perhaps it doesn't also cause hayfever