Ed and Linda Schmieding, of Adrian, were known for high-quality flowers grown in four greenhouses and on dozens of acres in three plots of land, using tractors and irrigation, The Detroit News reported Wednesday.
State police now believe the Schmiedings, both 60, were running one of the largest marijuana production facilities ever discovered in the Lower Peninsula.
Marijuana found in their greenhouses and on 23 acres of land was estimated to have a street value of at least $8 million, police said.
Acting on a tip, officers conducted a raid Monday on the Schmiedings' property, where the operation was obvious to anyone with a keen sense of smell, state police said.
"They could smell it from the road," Lt. Tim Gill, a detective with the state police, said.
Both Schmiedings were arrested without incident.
Ed Schmieding told police he sold the plants to medical marijuana dispensaries, a claim that hasn't been verified, Lt. Steve Galbreath of the state police said.
Police said Schmieding told them he has been growing marijuana since 2009, a claim that matches neighbors' accounts of the Schmiedings' scaling back their flower business.
"They slacked off big time last year," said Linda Kincer, who lives across the street. "He grew beautiful flowers."