What Pollens Cause Trouble?
Early springtime allergy is most often caused by pollens or common trees such as elm, maple, birch, poplar, beech, ash, oak, walnut, sycamore, cypress, hickory, mountain cedar, pecan, cottonwood and alder. Late springtime pollens come from the grasses, i.e. timothy, orchard, red top, sweet vernal, Bermuda , Johnson and some bluegrasses. Colorful or fragrant flowering plants rarely cause allergy, because their pollens are too heavy to be airborne. They rely on insects (bees and butterflies) to carry their pollens from one plant to another. The most significant allergy producing pollen in the United States comes from ragweed. It begins pollinating in late August and continues through October or until the first frost. Other allergenic weeds of lesser importance also pollinate in this season.
