Question: Can you settle a dispute between my garden buddy and me? Does goldenrod (Solidago spp.) cause hay fever? He planted it in his garden, and I'm suggesting he stock up on allergy medicine.
Answer: No, goldenrod doesn't cause hay fever, contrary to popular belief. Goldenrods are held guilty by association. They (Solidago spp.) bloom from late summer up to the frost. This is the same bloom period as ragweed (Ambrosia spp.), the true cause of hay fever.
The confusion relates to pollination. Goldenrods have beautiful large, long clusters of dark gold flowers. They have a fuzzy-looking texture. These highly conspicuous flowers serve the plant by attracting many different species of insects. They pollinate the plants, allowing them to set seed and spread.
Ragweed, on the other hand, is pollinated by the wind. A ragweed plant releases billions of lightweight pollen grains to increase the chances that the wind will carry some to another ragweed. These light pollen grains also find their way into our homes (and sinuses), and they can cause sneezing, itching and the other agonies of hay fever. Goldenrod pollen is heavy and sticky, so that it will cling to pollinating insects. It does not fly through the air.
So why do we blame goldenrod instead of ragweed? Probably because goldenrod flowers are so showy. Ragweed's green flowers are inconspicuous. It makes sense that people suffering from allergies suspect the plant that they can see is in full, abundant bloom.
There are many species and cultivars of goldenrod for possible inclusion in gardens. Some spread quickly by seed and by their roots, and can take over a garden. The Chicago Botanic Garden has good advice on choosing and growing goldenrods. Click here to see their goldenrod page.
Image: public domain