If you’ve been walking around Windsor lately wondering “what kind of fluff is this?” you’re not alone.
Poplar cotton — the white, almost snow-like substance that comes off the trees and collects in grasses and potholes — appears to be particularly abundant this year and is a sure sign that allergy season is here, experts say.
The fluff is a collection of seed hairs from trees in the tree family, which includes poplars, aspens and willows, said Sandy MacDonald, a professor of landscape horticulture at St. Clair College.
“This is a way for the tree to spread seeds,” MacDonald said. “In that down there is a little tiny seed and that is of course for dispersal. That seed can then float to another location, sometimes even miles away.
“Once it’s moist, it can germinate. And of course this is a way for the plant to reproduce.”
Poplar trees – taking their name from the Latin root “populus” – are, as their name suggests, quite popular across Canada. They are often planted in urban areas because they are fairly tolerant, MacDonald said: They can withstand the pollution, compacted soil, partial flooding and excess salt that often occur in cities.
Other common trees in the same family, such as willows and aspens, also produce the fluff — meaning Canadians from coast to coast will notice the stuff, he said.
Many people suffer from seasonal allergies this time of year and may be pointing the finger at the fluff. MacDonald said the fluff itself isn’t actually an allergen, but that’s not the end of the story.
Windsor morning8:29What is going on?
Sandy MacDonald, who teaches a landscape gardening program at St. Clair College, talks to CBC Windsor Morning host Nav Nanwa about poplar seed “fluff.”
“In some ways, it can be irritating to the eyes, nose, and throat if you inhale it…that can indicate irritation, and so could be mistaken for an allergy symptom,” MacDonald said.
“But there is also evidence that other pollen in the air, from other pollinating trees, can actually trap it … it also acts as a carrier.

“But technically, we don’t think most people are allergic to that fuzz itself.”
More people are going to the local pharmacist for seasonal allergies
Rob Modestino is the owner of Rob’s Whole Health Pharmacy in LaSalle. Seeing the fluff, he said, is a surefire way to know allergy season is coming.
“There are more people coming in this year than we’ve seen before saying they’ve ‘never had allergies before. Are we sure they’re allergies? Are we sure?’

“Most think it’s a cold, some sort of flu virus, or bacterial infections. And when you dig into it and get some information, you find out it’s allergies. It seems like the last few years have gotten a lot worse.”
Modestino said people should work to reduce their pollen exposure by closing windows and taking allergy medication if necessary. Symptoms to watch for include runny nose, itchy eyes, and sneezing.
People should talk to their pharmacist before using any allergy medication recommended by Modestino. This year, pharmacists can also review and prescribe allergy medications that could be more effective than the over-the-counter medications for people with more severe seasonal allergies.
More fluff than usual this year
There may be more fluff than usual, probably caused by the weather: Hot and dry weather over the past few weeks, lack of late frosts and the last two hot, dry summers that have been stressing the trees, and consequently the need for trees to grow more spreading seed could all play a role, MacDonald said.

The fluff is flammable, MacDonald said, so some people use it as a fire starter.
But people have also explored other uses: using it to stuff pillows and as a fiber. Neither works well. Turns out what it does best is what it needs to do.
“Even though they’re very fine… there’s a central hollow core and that actually helps hold water for the germinating seeds,” he said.
“The structure of it is really very interesting and of course works perfectly for the germinating seed.”