I was curious if these fruit-bearing trees were actually more common in Portland or if I just noticed them more now that I started foraging. Thomas Leo Ogren talks about a term called, botanical sexism, which refers to the planting of male trees (specifically, cloned males) in landscaping to avoid the “litter” from fruits and seed pods. He goes on to argue that this phenomenon has increased pollen production and thus seasonal allergies. Female trees don’t produce pollen, they actually use pollen in the air to produce their seeds.


While Ogren’s theory was recently popularized by TikTok, it has also been challenged. (The Complicated Truth Behind ‘Botanical Sexism’). Jane C. Hu talks to urban ecologist Rita Sousa Silva to add some nuance to the conversation. Hu explains that at the time the article was written, there wasn’t enough data to suggest that there actually are more male trees planted than females. Silva describes that, while considering the “mess” of fruit and seeds may be part of a landscaping decision, often the tree’s aesthetics or use — colour or the kind of fruit – is a better indicator of buying preference over the tree’s sex. She goes on to argue that it may be climate change that’s worsening allergies, triggering plants to release more pollen as the allergy season lengthens. Planting a diversity of trees, such as those pollinated by insects instead of wind, may provide a better solution than removing pollen-producing male trees.