Fuzzy seeds in Chicago cause of allergies, congestion in residents

Seasonal weather has again caused white stuff to fall from Chicago skies - and this time it’s not snow.

“The fuzzy seeds floating around are coming from eastern cottonwood trees,” said Sara Calapiz, horticultural specialist at the Chicago Botanical Garden. “It happens annually, during June or July, depending on the weather.”

The eastern cottonwood tree, or populus deltoides, is one of North America’s largest hardwood trees. Its native habitat stretches from Quebec to the eastern U.S., and it’s also found in parts of Florida, Texas, and Kansas.

But recently the fluffy seeds of the tree can be found in downtown Chicago.

“A lot of people don’t want to plant these trees because the seeds are messy,” Calapiz said. “Still, it’s something I look forward to seeing because it’s a sign of summer.”

Another sign of summer, according to Say Nimmagadda, allergist and asthma specialist, is the “summer cold”—allergic reactions to settling pollination, high humidity levels, and mold.

“Basically in the Midwest, you’re going to get everything from April to October,” he said. “You’re going to get something blooming that causes allergies for the next six months.”

Typically, plant pollination starts around April and last between six to eight weeks. The floating white puffs of eastern cottonwood seeds mark the end of the pollination season.

However, Nimmagadda added that this year’s unusually long winter has thrown everything off track.

“It’s particularly heavy this year,” he said. “I think the trees are all releasing pollen at one time. My patients are coming in to me and complaining that their eyes are itching, they’re congested. Lately, it’s been a real problem.”

People working in the Loop have are aware of the unusually heavy cotton seeds piling on the sidewalks.

“I’ve lived in Chicago pretty much all my life, and I’ve always wondered what they are,” Edgar Gonzalez, 37, said. “I generally don’t consider them a nuisance, but I’ve never really noticed a pattern, until now.”

While the tree’s pollination comes with little surprise to long-time Chicagoans, Northbrook resident Cheryl Braude said she agrees that this year is different.

“It’s strange to see so much of the seeds in the city,” she said. “They’re no trees downtown, yet you see them floating everywhere.”

Increased wind patterns could also be to blame for the swarming clouds of cotton seeds, Calapiz said. Whatever the cause of it, Braude said it’s anything but common.

“It’s the first time I’ve seen something like that in the Loop.”