Goldenrod is often cited as the cause of hay fever simply because it's so brilliant at a time when its humble but potent cousin, ragweed, is also blooming. As a result, misguided allergy sufferers destroy countless goldenrods, one of the great seasonal sources of color and scent as well as nectar for bees.
Airborne pollen causes hay fever. Most flowers with airborne pollen – ragweed, plantain, grasses, many trees – are green and unnoticed, hidden among their own leaves. They're green because they don't need to be “different” to catch the eye of passing bees and other flying pollinators – they use air, not insects, to effect pollination. Goldenrod has bee-borne pollen, too heavy to float in the air and up the nose. Its yellow helps attract bees to haul its pollen around.
Thus, despite all the colorful TV and magazine ads for allergy medications, few if any brightly colored flowers will ever tickle your nose or tighten your chest. Wheezers and sneezers should join everyone else and enjoy Mother Nature's late summer explosion of yellow.