Nobody ever signed up for an allergy, but it creeps in spring after spring after spring. Trapped in a runny nose limbo, you look for a reason, scrolling miles in Google search like it was a long distance marathon. With few results.

Landscaping expert and allergy-friendly tree planning advocate Thomas Ogren has been studying the link between landscape plants and allergies for years. But when he started taking pics of trees to use as slides for talks, he couldn’t find any female ones. Thomas had to dig deeper to find the cause. And it turns out, the whole neighborhood was planted with male trees only as a result of a 1949 USDA Yearbook recommendation. That’s how Thomas’ “sexist trees” theory, which has now resurfaced thanks to the thread below, came about.

Scroll down for our interview with Thomas down below to see what else he had to say about his remarkable theory!

Update: This post incorrectly stated that the said scientist tried combating his wife’s allergies after buying a house together. He didn’t buy a house and it was not his wife’s allergies that was the main reason behind his research

More info: Allergy-FreeGardening.com

Twitter user Antonia recounted Ogren’s theory of allergy in a now-viral thread

Image credits: Flaminhaystack

Bored Panda spoke to Thomas about how he found that that male trees cause more allergy. After Thomas started taking close-up photos of flowers of different species of trees, he realized that only the male trees made the pollen. “I wanted to get photos of both male flowers and female flowers to show as slides at these talks.” But he couldn’t find any female trees.

Contrary to what the thread claims, Thomas himself didn’t buy a house for his allergy-prone wife. He was walking down a street with his camera when he came upon a house with a large native coyote bush in bloom.

“As I started taking photos of the flowers, a man came out and asked me ‘What’s so interesting about my yard?’” Thomas told him how his groundcover was all male and producing pollen, which is allergenic. He recounted: “’Hmmm,’ the man said, ‘I wonder if that’s why my wife’s allergies are so bad?'”

Image credits: Flaminhaystack

Image credits: Flaminhaystack

Image credits: Flaminhaystack

Around this time, Thomas read the 1949 USDA Yearbook, called “Trees.” “In the section about red maples, I read this advice: since these trees are all separate-sexed (dioecious), if you take all your scion wood (for grafting) only from male trees, then all the trees you produce to sell will be seedless and litter-free,” he explained.

He soon found the same phenomena in other towns nearby. And eventually, “I found this held true almost everywhere in the world I went: England, Israel, Canada, New Zealand, Australia. All their city landscapes were male-dominant,” said Thomas.

Image credits: Flaminhaystack

Image credits: Flaminhaystack

Image credits: Flaminhaystack

Image credits: Flaminhaystack

According to Thomas, the beauty of female plants is that “they never shed any pollen, ever.” Plus, “female plants trap and remove pollen from the air.” But since there are so many pollen-pumping males in cities, “the pollen has nowhere to go… except up our noses.”Thomas summed up that “Botanical sexism is alive and well, alas, and with it, allergy and allergic-asthma continue to get worse and ever more common.”

Thomas wrote about his life-long research on plants and allergies in the book titled “Allergy-Free Gardening.”

Antonia shared some solid facts for people on Twitter who couldn’t believe it’s real

Image credits: Flaminhaystack

Image credits: Flaminhaystack

She also posted a recommendation from the European Commission to plant more female trees

Image credits: Flaminhaystack

Image credits: Flaminhaystack

The Centers for Disease Control and Prevention reports that more than 25 million Americans—7.7 percent of adults and 8.4 percent of children—have asthma. According to WHO estimates, approximately 250,000 people die prematurely each year from asthma around the world.

Many were left stunned by this remarkable explanation

Image credits: IncognitoPengy

Image credits: Flaminhaystack

Image credits: JakxEliades

Image credits: YuehNing3

Image credits: amateuradam

Image credits: JeanetteHall9

Image credits: JeanetteHall9

Image credits: Clo_vdn

Image credits: thegratefulgran

Image credits: SarahJay55

Image credits: cvhdavidblues

Image credits: AdriaenMorse