David Morrow steps out of a minivan parked outside Lume’s sprawling 225,000-square-foot facility in Everett, Michigan, walks through the front door and puts on a Tyvek coverall and shoe covers. Then he enters an air shower, a narrow corridor that releases purified air to remove pests, mold and viruses that may be crawling on his hair, skin and clothes.

“It kills all the hitchhikers,” Morrow says, explaining that his seven-year-old cannabis company has never lost yield thanks to almost obsessive biosecurity measures. “One little thing can kill a crop.” Once in the center of the warehouse, he washes his hands, puts on a face mask and hair net, and opens the door to Grow Room 10, revealing about 900 high-quality marijuana plants, about three feet tall with big, fat buds reaching for LEDs.

“Every time I come here, it’s like an out-of-body experience,” says Morrow, 55, who founded Lume with Belle Tire magnates and brothers Robert and Donald Barnes in 2019. “I can’t believe we have a weed factory.”