This agricultural underworld is likely all across the Corn Belt of the United States, and has been for decades, as highlighted in Dr. Ralph Weisheit’s 1992 book, Domestic Marijuana: A Neglected Industry. Yet it never appears in the numeric representations of corn growing, like the agricultural census. Nor does it appear in life cycle analyses, such as “King Corn,” the popular 2007 documentary attempt to demonstrate the seed to table journey of corn in the U.S. (While those filmmakers found hemp growing in their field, it was of the industrial rope variety.) As Lieutenant Jason Freedman of the Dane County Narcotics Task Force recently told me: “It is occurring all over the county. Even though they are small operations and subject to weather, outdoor growers are the primary source of local production. That was not the case 10 years ago.” Elyse Schaffer, the public information officer for the Dane County Sheriff's office, confirmed: “We definitely find those grows on a regular basis.”

All the corn farmers I’ve spoken with who have found marijuana in their fields report it to the local authorities, even though traditional reporting of drug crimes and arrests don’t capture this reality. While the DEA reports that it eradicated over 4 million marijuana plants cultivated outdoors in 2013, it would take a formal Freedom of Information Act request for even the chance to find out how often or where these growing incidents occur in corn. Lieutenant Freedman estimated that “less than 10%” of the marijuana his group seized in the past few years has come from corn fields. He acknowledged that marijuana grows in corn fields don’t appear in reports like annual records of confiscations and arrests in large part because they are rarely discovered and even more rarely result in an arrest: “They are anonymous and hiding in plain sight; law enforcement is much less likely to come across them [than indoor growing operations.] A very small percentage of outdoor grows lead to an arrest. Has it happened? Yes, but single digits.”

The farmers I work with here in Wisconsin, where corn is worth $2.2 billion a year, seem both annoyed and bemused by this trend. The average farmer is growing food on 195 acres; some of them have thousands. One family I work with is a third-generation farm growing on 2,000 acres—over half of which are corn. The past several years they have found marijuana growing in at least one of their fields during harvest and reported it to the police. (The family asked not to be identified in this article, citing privacy concerns.) Sometimes they catch it before the growers harvest the marijuana, other times not. In 2010, they found an unusually large patch, two rows of 400 plants along a field edge that had yet to be harvested. The local cops staked it out overnight but the marijuana growers never showed. The DEA was called in to cut down and burn the contraband. Knowing the time, energy, and money that go into a crop, the family cursed the idea that someone was freeloading on their good soil and irrigation.