If you didn’t even know trees came in male and female varieties—or that there’s a botanical sexism problem involving them in the U.S.—you’re not alone. But you’re about to find out.

Claritin is launching a campaign to counter misguided practices dating back decades that led to cities and landscapers planting too many male trees, which spew pollen and cause allergies.

Bayer’s DiversiTree Project is backed by a social video campaign from Energy BBDO in which Claritin is joining with the National Arbor Day Foundation’s Community Canopy program to distribute a limited number of free female trees to people who will plant them. These are small trees, not seedlings since it’s impossible to tell the gender of seedlings.