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The Debunker: Are Flowers Bad For Your Allergies?

by Ken Jennings

Spring is turning to summer here in the Northern Hemisphere, and the world is in blossom. Flowers always make me think of Chairman Mao, who once vowed to “let a hundred flowers bloom” in China, meaning that the nation would be healthier if a diversity of ideas could compete for attention. But in real life, sometimes the wrong flowers win the war of ideas, leading us up a primrose path of misconceptions and misinformation. This month, Jeopardy! champ Ken Jennings digs up all kinds of floral falsehoods from the fertile soil of his mind, separating the weeds of legend from the pick-me-up bouquet… of truth.

Flower Myth #3: Stay Away from Flowers If You Have Seasonal Allergies!

Allergies are often at their worst in the springtime, when big, beautiful flowers are conspicuously blooming all over the place. As a result, they were long blamed for causing all the sniffling and the sneezing. Hay fever was even called “rose fever” during the Victorian era and afterward.

In his 2000 book Allergy-Free Gardening, horticulturist Tom Ogren created OPALS, the Ogren Plant Allergy Scale, which ranks plants’ sneeze-causing potential from 1 to 10. (Hollyhocks are a 2, for example, while the dreaded bottlebrush is a solid 9.) Ogren’s results have codified what allergists have been saying for years: the prettier a flower is, the less likely it is to cause hay fever. Flowers with big, brightly colored blooms have evolved that way to attract the birds and bees that pollinate them, and biotically pollinated species tend to have larger, less irritating pollen. What really gets up your nose are the dust-like pollen grains of plants that are “anemophilous”—pollinated by the wind. In other words, non-showy species like trees and grasses are usually the worst hay fever culprits. Ornamental flowers are, contrary to popular belief, the safest of plants.

Of course, there are lots of different kinds of noses out there, and some people are sensitive enough that they have to avoid flowers. But allergist Richard Weber says that’s not typically a pollen issue. “When people do have trouble with flowers, it's usually because they are sensitive to a flower's strong smell. They have nonallergic rhinitis—not an allergy.” You should feel confident that you can hand almost anyone a nice bouquet without providing a follow-up gift of Claritin.

Quick Quiz: What plants in genus Ambrosia—ironically, the mythical “food of the gods”—are the leading cause of hay fever in North America?

Ken Jennings is the author of Brainiac, Ken Jennings's Trivia Almanac, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at or on Twitter as @KenJennings.

Photo by Flickr user parislemon. Used under a Creative Commons License.