The USDA and agriculture officials across the U.S. have issued warnings about unsolicited shipments of foreign seeds and advised people not to plant them. Officials are concerned the mystery seeds, which appear to have originated in China, could be invasive plant species.
CBS News has confirmed that residents in all 50 states have now reported receiving suspicious packages of seeds.
"USDA is aware that people across the country have received suspicious, unsolicited packages of seed that appear to be coming from China," the USDA's Animal and Plant Health Inspection Service (APHIS) said in a statement Tuesday.
It said it is working closely with federal and state partners, including Customs and Border Protection, to investigate.
"Pls don't plant seeds from unknown origins!" the agency tweeted.
State agriculture officials in Virginia warned, "Invasive species wreak havoc on the environment, displace or destroy native plants and insects and severely damage crops. Taking steps to prevent their introduction is the most effective method of reducing both the risk of infestations and the cost to control and mitigate those infestations."
In Kentucky, the state agriculture department was notified that several residents received unsolicited seed packets sent by mail that appeared to have originated in China, Agriculture Commissioner Ryan Quarles said earlier. The types of seeds are unknown and could be harmful, he said, stressing they should not be planted.
"We don't know what they are, and we cannot risk any harm whatsoever to agricultural production in the United States," he said. "We have the safest, most abundant food supply in the world and we need to keep it that way."
Anyone in Kentucky receiving packages of foreign or unfamiliar seeds should contact the state agriculture department immediately, Quarles said.
"At this point in time, we don't have enough information to know if this is a hoax, a prank, an internet scam or an act of agricultural bio-terrorism," he said. "Unsolicited seeds could be invasive and introduce unknown diseases to local plants, harm livestock or threaten our environment."
APHIS said the USDA is collecting seed packets from people who received them and will test the contents to see if they contain anything that "could be of concern to U.S. agriculture or the environment."
But it also said that as of Tuesday, it didn't have "any evidence indicating this is something other than a 'brushing scam' where people receive unsolicited items from a seller who then posts false customer reviews to boost sales."
In North Carolina, the Department of Agriculture and Consumer Services said it was contacted by numerous people who received seed shipments they did not order. The agency said the shipments were likely the product of the international internet scam known as "brushing."
"According to the Better Business Bureau, foreign, third-party sellers use your address and Amazon information to generate a fake sale and positive review to boost their product ratings," said Phil Wilson, director of the state's Plant Industry Division.
New York Commissioner of Agriculture Richard Ball said in a statement Monday that his office had also fielded "a few" queries from residents who got unsolicited "packages allegedly sent from China that are marked as containing jewelry but which actually contain plant seeds."
Ball confirmed that the USDA was investigating, and told residents not to handle or plant the seeds.
He said anyone who gets a packet of seeds "should store them safely in a place children and pets cannot access," and then email the USDA immediately at email@example.com with their full names and phone numbers, pictures of the packaging, "and any other relevant information."
The USDA later urged anyone who receives an unsolicited seed package to contact their state plant regulatory official or APHIS State plant health director immediately. "Please hold onto the seeds and packaging, including the mailing label, until someone from your State department of agriculture or APHIS contacts you with further instructions. Do not plant seeds from unknown origins," it said Tuesday.
Maryland agriculture officials said in a tweet they were working with the USDA to investigate seeds sent to residents there and warned people not to plant them.
Virginia's Department of Agriculture issued a similar warning.
"The types of seeds in the packages are unknown at this time and may be invasive plant species. The packages were sent by mail and may have Chinese writing on them," the Virginia Department of Agriculture and Consumer Services said in a statement last week, adding: "Please do not plant these seeds."