By Bonnie Berkowitz and Patterson Clark, Published: April 2, 2014
Trees that usually flower in February and March are just waiting for a few warm, sunny days to release their pollen. They are expected to overlap with trees that usually flower in April, possibly creating concentrated misery for allergy sufferers in coming weeks. Read related article.
SOURCE: Susan Kosisky of the U.S. Army Allergen Extract Lab; “Pollen aeroallergens in the Washington, D.C., metropolitan area: A 10-year volumetric survey (1998-2007)” by Kosisky, et al.