Feral cannabis, or wild marijuana (often referred to in North America as ditch weed), is wild-growing cannabis generally descended from industrial hemp plants previously cultivated for fiber, with low or negligible amounts of psychoactive tetrahydrocannabinol (THC).
[1] Industrial hemp was widely cultivated in the American Midwest in the mid-20th century, particularly to support the war effort during World War II, and since that period the plant has re-seeded naturally and grown wild in states such as Oklahoma, Missouri, Nebraska, Iowa, and Minnesota, with Indiana reporting the largest concentrations nationally.
"[2] Responses to feral cannabis vary by time period and jurisdiction, with some entities putting out efforts to eradicate the plant, while others consider it a very low priority.
[citation needed] Feral cannabis is an exceptionally hardy weed, widely dispersing its seeds which can lie dormant for 7–10 years before sprouting again.
[4] In Minnesota, hemp is classified among the 11 "noxious prohibited weeds" along with several species of thistle, and noted for damaging farmers' plowing equipment.