The Minnesota Department of Agriculture says it has now received hundreds of reports of mysterious seeds arriving unsolicited in the mail.
State officials issued an alert over the seeds earlier this week, saying they were possibly coming from China or other eastern Asia countries, and has since received more than 700 reports from Minnesotans.
While initially unsure what the seeds were, MDA analysis have since confirmed some of them to be cosmos, radish, mung bean, juniper, basil, cucurbit, and zinnia.
While none of these are invasive plants, the MDA says the seeds "may carry disease and pests can hide in packaging."
"So far, there is no indication these unsolicited seeds have gone through appropriate inspection or that they are properly labeled," it added.
The department says it's working with the United States Department of Agriculture (USDA) on the problem, with there having been similar reports of seed packages arriving in several other states.
The USDA suggests it might be a "brushing scam" where individuals receive "unsolicited items from a seller who then posts false customer reviews to boost sales."
Those getting the seeds have told MDA they have never made an online seed order, or bought seeds online earlier in the year but never received them.
Anyone who gets the seeds should save them and report it to the MDA here. Do not open the seed packets or plant the seeds, and if the packets are already open, place them in a tightly-sealed plastiv bag.
If you've already planted them, destroy any that have germinated. After pulling them up, double bag them and the surrounding soil, and put them in your regular trash.