It happened three times in just two days.
Officials say it's not the seeds themselves that are dangerous, but rather what's on the packaging.
"Out of caution, if you get something that you didn't order, be suspicious of it," Captain Tony Augustine said.
They say it may be part of a larger nationwide scam.
The seeds started arriving in mailboxes throughout Brookfield last Friday.
One concerned resident drove the packet to police headquarters, triggering a hazmat response from the fire department and the Connecticut Department of Energy and Environmental Protection.
"They tested the substance in the car they found at that time that it wasn't a hazardous substance, that it was some type of seeds," Cpt. Augustine said.
Seed scams are not new.
In 2020, New York State issued an alert advising residents not to plant unsolicited seeds, which are usually from China and could introduce invasive species.
Testing had determined the contents to be a mix of ornamental fruit and vegetables, herbs and weeds.
Such mailings are considered to be part of what's called a brushing scam.
That's when sellers ship inexpensive items and then post fake reviews in an attempt to boost sales.
This year, people in Alabama, New Mexico and Texas have also reported receiving seeds.
Mary Yates lives on the block where two of her neighbors received seeds last week and an unsolicited package arrived in her mailbox last year.
"I thought maybe my husband ordered them, but after checking with him, neither one of us had ordered them and I checked with my sister and she said in New York State, they've been getting them," Yates said.
Residents are advised to not open the package nor scan the QR code on the label and to wrap the packet in duct tape, then dispose of it in the trash.
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