Wind-borne pollens are the primary cause of hay fever. Any plant with showy flowers (like the much-maligned goldenrod) is pollinated by insects, not wind. The main hay fever culprit in our area is ragweed, which thrives in disturbed or eroded areas like roadsides. Other major allergenic plants are pigweed, goosefoot (both non-native “weeds”), and the non-native grasses in turf lawns or pastures–Kentucky bluegrass, Bermuda grass, and timothy. Some tree species with wind-borne pollen, such as oak, also are allergenic.
Perennial native plants and native grasses, the primary components of natural landscapes, generally do not produce wind-borne, allergenic pollen. In fact, encouraging these species to grow crowds out weedy pioneer species like ragweed that germinate and thrive at lawn edges.