Battle of the sexes : the history of botanical sexism & your allergies

By: Gabbi Di Marino, fellow allergy sufferer and content manager

Who knew sexism was so widely spread that it even affects the way we landscape? I sure as heck didn’t. In this piece, I’ll be breaking down where and when this problem first started and why we need to introduce more female trees into our environment.

The history of botanical sexism

This epidemic first started with a simple tip of advice from arborists (tree experts) in 1949. They advised street-planters to use only male trees. Why? To eliminate the “litter” or seeds that female trees inevitably drop. Based on this tip, the USDA then began developing hundreds of new maple trees and hybrid clones of trees that were all male. And it wasn’t just the USDA that made new, all-male trees. Wholesale growers also got in on the action by creating trees that never existed before, trees like the seedless Cyprus and pod-less honey locust trees. And that wasn’t enough either. Commercial growers even went as far as producing a plethora of all-male shrubs, fern pines, junipers, and even all-male hanging basket plants! While these plants produce no seeds, they do produce a ton (and I mean a TON) of allergy-inducing pollen! 

But this didn’t really become a problem until the 1970s when a Dutch elm disease hit. Prior to this outbreak, the need for street-planting was minimal - the majority of America’s streets were already lined with beautiful, stately American elm trees. But when this disease reared its ugly head, millions of trees began dying off and the need for replanting the streets suddenly became a high priority. Instead of sticking with the insect-pollinated Elm trees, city’s instead chose wind-pollinated, all-male trees. These trees took a few years to bloom, but when they did, the pollen they released couldn’t be missed. The majority are still alive and well, but this isn’t a good thing - as they grow, they only release more and more pollen! 

And while these trees are technically wind-pollinated, the majority of their pollen won’t float far, far away, but in fact, will land within 20-30 feet from the tree itself. This is the root of the problem of “proximity pollinosis”: allergies caused by the pollen closest to you. So, this isn’t something we can run from. Instead, there needs to be a systemic change in the way we plant. 

The needed shift towards female species of trees

In order to address the allergy epidemic facing our country, we have to face the fact that the way we’ve been landscaping our environment just isn’t sustainable anymore. There are some cities in the U.S. that are ahead of the curve, banning the sale and planting of the worst offenders, but the majority of our country has yet to join in, meaning male trees are still dominating the outside. But why are female trees needed? For starters, they produce no pollen. That’s right, no pollen! Not only that, but they even trap pollen in the air and turn it into their seeds, which they will then drop. Think of them as allergy-busting superheroes - the more female trees we have, the less pollen will be floating free in the air, which is good news for all of us! 

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