Michigan will ban untreated firewood from entering the state beginning January 1, 2027, the Michigan Department of Natural Resources announced. Only heat-treated and certified firewood will be permitted across state lines.
The ban aims to prevent the spread of invasive forest pests that have devastated Michigan's forests. The emerald ash borer, which spread partly through firewood movement, has killed an estimated 40 million trees since 2002, the department said. Oak wilt fungus can kill oaks within months, and spotted lanternfly—now in Michigan's southern Lower Peninsula—could spread northward through untreated wood.
The Michigan Invasive Species Program has established a certification program allowing firewood producers to have their heat-treatment processes certified by the state. Certified wood will bear a state certification seal equivalent to federal USDA-certified heat-treated firewood.
Until the ban takes effect, state officials urge residents not to move firewood more than 10 miles from where it was cut unless it has been heat-treated and certified. The department emphasized that aged or seasoned wood is not safe to transport—a recent study found insects emerging from firewood even three years after it had been cut.
More than half of Michigan is forested with an estimated 14 billion trees, the department said.