Tree-based sexism: "Decades of urban landscaping sexism are partly to blame for high pollen counts."

Yes, of course I have a link to match the meme.

Sniffling and sneezing? Too many male trees are (partly) to blame, by Aimee Custis (Greater Greater Washington)

With February's early warm weather, DC's pollen counts are climbing earlier than usual. What you might not know is that decades of urban landscaping sexism are partly to blame for high pollen counts.

That's tree-based, not people-based, sexism. Some common types of trees used in urban landscaping are dioecious, meaning individual trees are either male or female.

When it comes to dioecious plants, cities tend to prefer planting males to females because females drop fruit or seeds that the city then needs to clean up. The most notorious female offenders are gingko trees, whose undesirable smelly fruit plague residents with "strong notes of unwashed feet and Diaper Genie, with noticeable hints of spoiled butter."

But male dioecious trees don't drop seeds or fruit. Instead, in the spring, they release pollen.

With February's early warm weather, DC's pollen counts are climbing earlier than usual. What you might not know is that decades of urban landscaping sexism are partly to blame for high pollen counts.

That's tree-based, not people-based, sexism. Some common types of trees used in urban landscaping are dioecious, meaning individual trees are either male or female.

When it comes to dioecious plants, cities tend to prefer planting males to females because females drop fruit or seeds that the city then needs to clean up. The most notorious female offenders are gingko trees, whose undesirable smelly fruit plague residents with "strong notes of unwashed feet and Diaper Genie, with noticeable hints of spoiled butter."

But male dioecious trees don't drop seeds or fruit. Instead, in the spring, they release pollen.

Horticultural epidemiologist Tom Ogren traces the modern preference for male trees to around 1950, when the USDA released a book that promoted planting male trees over female trees for easy, litter-free maintenance. The idea caught on with private homeowners, nursery suppliers, and city planners. At the time, Dutch Elm disease was on the uptick, and swaths of trees in US cities were being replaced. Today, DDOT's Design and Engineering Manual (section 47.4.4) confirms that "...trees near walks should be thornless and fruitless to minimize maintenance," though of course there are plenty of fruitless trees that aren't dioecious males.

Favoring male trees isn't a bad idea in itself, and Ogren believes no one had any bad intentions. "But when a city does this on a massive scale, it has a huge impact on the health of the people who live there," he said to Governing. Ogren, who developed the Ogren Plants Allergy Scale (OPALS) used by the USDA and American Lung Association, says planting more female trees will reduce the pollen count in a city.

That makes sense. The job of female trees is to capture pollen, essentially acting as natural air filters. But when they're nearly non-existent, we're left with a ton of pollen in the air with no females to trap it ...