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.
The Bayer brand’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.
Claritin’s campaign addresses a policy dating at least to a 1949 U.S. Department of Agriculture guide, which encouraged cities to plant mainly male trees because male trees don’t produce fruit and thus make less mess on sidewalks. Many landscapers have favored male trees for the same reason.
The problem is that male trees produce lots of pollen. And without female trees to absorb it, that pollen spreads far and wide and causes allergies. In the wild, female trees often outnumber males, since a single male can pollinate many female trees. But in cities, that ratio is often flipped, leading to lots of excess pollen.
“We were doing some research around different ways to activate out in culture for Claritin and came upon this fact and this USDA recommendation around planting male trees,” said Katie Clow, global client lead for Bayer Consumer Health at Energy BBDO. The issue was raised in a viral 2021 TikTok video, but remains widely unknown.
“If people even know that there are male and female trees, they certainly aren’t thinking about the impact on pollen and allergies,” Clow said. “We love to talk about the sort of botanical imbalance in male and female trees and the way that’s been perpetuated over time without real awareness around it. We felt this was something just truly powerful to unearth, and found a really wonderful way to do that with the DiverisTree Project.”
Beyond the female trees that get distributed, the campaign should help raise awareness about the issue among homeowners and nurseries, where trees today often aren’t labeled as male and female, Clow said.
“Claritin is on a mission to help reduce pollen levels and restore botanical balance,” said Catherine Vennat, VP and general manager for upper respiratory at Bayer, in a statement. “Through female tree plantings in cities across the country, we’re aiming to help communities one tree at a time and are committed to research within the field of plant science, all with the goal of having everyone enjoy the outdoors every day.”
Claritin also is hosting female tree-planting events in two cities ranked by the Asthma and Allergy Foundation of America as some of the hardest places to live with allergies—New Orleans and Richmond, Virginia. And the brand is conducting a study to be released on April 7 in partnership with Dan Katz, senior research fellow at the School of Integrative Plant Science at Cornell University, on the potential for planting low-pollen trees, including female trees, to reduce airborne pollen concentrations in New York City over the next 50 years.
Beyond the pollen issue, tree gender is complicated, in part because trees, particularly within some species of maple, sometimes spontaneously change genders. Only about 20% of trees in the Eastern U.S. are dioecious, where entire trees are strictly male or female. Most are co-sexual, with flowers that have both male and female parts fully functioning—or polygamous, with a mix of male and female flowers on the same tree.
