Was there ever a more capable foe
Than one who shields his strength so?
An unremarkable plant, heavy with seed
cast to the wind with resolve and speed.
As his fecundity causes grief both far and wide,
from behind fairer bloom, he shrinks to hide.
Between sniffles, I must confess a grudging admiration for the homely Ambrosia artemisiifolia, that bane of late summer and fall that we know as common ragweed. That’s why I even wrote the little verse above in its honor.
As a dabbler in the garden, I’m hard-pressed to think of another annual that can release up to a billion grains of pollen from just one solitary plant. Not that ragweed is ever terribly alone, growing in abundance as it does throughout central and eastern North America from the Southern states far up into most of Canada.
One North Dakota agronomist estimates that in the United States alone, 250,000 tons of ragweed pollen is released into the air in a year. The tiny seeds that can journey up to 400 miles to find the right pollen sufferer’s nose to pester.
Ragweed is an able adversary, which makes its mark on millions of lives. Consider the allergy industry this inelegant weed has spawned. There are the teams of scientists trying to create the better pill or spray to stem the flow of the sinuses, the weeping eyes, and the bleary-headedness. Then all the pharmacies selling the medications to business people who claw at itchy eyes and whose children practice the “allergic salute” – that palm up swipe of the nose.
Think, too, of the enormous costs to the economy in sick days when the allergy symptoms get too bad to bear. It’s all thanks to this nondescript procreating machine with its beady little flowers.
Where I live in southern Ontario, July is always hot and sticky. You’re lucky if the begonias don’t suffer meltdown, while the cone flowers keel.
Common Ragweed: Any Dirt Patch Will Do
But Ambrosia artemisiifolia and its taller and almost as virile cousin Ambrosia trifida (giant ragweed) are not that precious. These hardy, rough boys love nothing more than to sprout up in vacant lots and alongside highways and railroad tracks. As some of us cultivate, fertilize and cajole our gardens, they’ll take root in any patch of dirt.
At least giant ragweed grows tall enough (up to 13 feet) to notice. Common ragweed is often overlooked in fields and parks. Showier plants, such as goldenrod, are mistaken for ragweed, maligned and uprooted, while the real culprit stands off to the side or, more likely, down at the local vacant lot – like a teenager up to no good.
“Inconspicuous” is the adjective botanists usually employ to describe common ragweed’s gray-green branches, leaves and greenish-yellow flowers. And so it goes – and grows – unnoticed and building toward a crescendo of airborne suffering. Only the frost ends its reign of misery.
Our adversary is a survivor without peer. Its seeds can lay dormant for up to 40 years and still germinate if disturbed. Crop farmers in the United States are reporting that both common ragweed and its giant cousin are becoming resistant to glyphosate, the king of herbicides. And there are stories of ragweed springing forth through newly laid asphalt or concrete. Like a creature from science fiction, ragweed just keeps on coming.
But as you sneeze and curse the dratted weed, wondering how one pest of a plant can cause so much grief, think again. You’re not just fighting your allergies, you’re battling a feat of science, a dastardly little marvel of genetic engineering.