Mysterious seeds of possible foreign origin showing up in Wisconsin mailboxes. Don’t plant them.

The Agriculture Department is looking into the origins of mysterious packages of seeds with Chinese mailing addresses delivered to recipients who say they never ordered them.

Wisconsin joins the list of states whose residents have received strange, unsolicited packages of seeds in the mail. 

On Tuesday, the Wisconsin Department of Agriculture, Trade and Consumer Protection released a statement about the packages, which have been showing up in other states.

The packages appear to have come from China, but there are still many unanswered questions about the content and origin of these packages.

The state cautions residents not to plant or throw away any unidentified seeds they receive through the mail. The seeds may belong to invasive species or could carry diseases that could infect local plants. 

Anyone who receives these seeds should report the packages to the DATCP through this online form. The state will work with the United States Department of Agriculture’s Animal and Plant Health Inspection Service to follow up on any reports.

The federal agency “will likely be doing site visits to collect seeds or plants for anything planted in the ground, and asking recipients to send material back to them for their investigations,” said Greg Helmbrecht, the seed programs manager in Wisconsin. 

The Department of Agriculture also advises recipients to save all packaging, which could provide clues for the origin and identity of the seeds. 

USDA officials believe that the seed packages are likely part of a “brushing scam” in which sellers send people unsolicited items and then post false reviews online in order to boost sales.

Any seeds that are shipped to the United States from other countries must have paperwork that shows the seeds do not contain any harmful pests or diseases. 

The New York Times reports that 27 states have now released warnings about these seed packages.

For more information, visit the WI DATCP and APHIS websites.

Jordan Nutting is a mass media fellow with the American Association for the Advancement of Science writing about science at the Journal Sentinel this summer. She’s working on a doctorate in organic chemistry at the University of Wisconsin-Madison.