Oct. 2, 2025
Contact: Susie Iott, 517-420-0473 or Joanne Foreman, 517-284-5814
Most people don’t spend much time thinking about firewood. If it’s split and dry, it’s good to go, right?
Well, maybe not. In recognition of Firewood Month, Michigan’s Invasive Species Program is taking a few minutes to unpack some firewood facts to help you make safe firewood choices to protect Michigan’s trees and forests.
Heating a home or enjoying a cozy evening by the fire is a great way to repurpose dead trees, but we often don’t think about what killed them.
Invasive insects like emerald ash borer or fungi like oak wilt can kill even healthy trees.
Other trees succumb to environmental conditions like drought, overcrowding or storm damage. Once a tree is weakened, it can become home to a host of insects and fungi that often remain in the wood even after it has been cut.
That means dead wood is often alive with harmful insects and diseases that can be transported to new locations on or in firewood.
What’s in my wood?
 Wood borers
“Wood borer” is a general term for beetles that lay eggs on or in the bark of trees. When eggs hatch, these insects spend their larval stages tunneling into and feeding on wood, destroying tissues that move sap and water through the tree.
Many wood borers are native and seek out weakened trees. Others, such as invasive emerald ash borer and the Asian longhorned beetle (found in nearby states), infest healthy trees and cause their decline and death.
Wood borer eggs and larvae can remain in wood after trees die. Because they often are under bark or within the wood itself, they can go unnoticed until they emerge as adults. A Michigan study of 1,045 firewood pieces transported by the public indicated 23% contained live borers and an additional 41% showed evidence of previous borer infestation. |
 Adelgids
Adelgids are small, soft-bodied insects that feed on coniferous plants like pines or firs using piercing/sucking mouthparts. Agencies and partners in Michigan’s Invasive Species Program are working hard to prevent the spread of hemlock woolly adelgid in west Michigan. The Michigan Department of Agriculture and Rural Development is managing balsam woolly adelgid in areas of Clare, Missaukee and Oceana counties.
Adelgids are hard to see with the naked eye and are usually detected by the small, white, cottony tufts they spin to protect their eggs. Over time, hemlock and balsam woolly adelgids can kill their host trees by depleting sap and preventing its circulation. |
Fungal diseases
Whether native or invasive, many types of fungi can cause tree death. Fungal diseases move around via spores or other structures and are spread in a variety of ways. Both invasive oak wilt and Dutch elm disease fungal spores can be spread by beetles. When trees die of fungal disease, the fungus can remain alive even if the wood is cut. Moving infected wood can spread tree diseases to areas far beyond a beetle’s range.
 Egg masses
For many Michiganders, spongy moths (formerly gypsy moths) and their munching caterpillars are all too familiar. While female moths can’t fly, they easily spread across the state by depositing egg masses on vehicles, outdoor equipment and firewood, which are then moved around by people.
With invasive spotted lanternfly now present in areas of southeast Michigan, the same scenario is likely to play out again unless we all take the time to look for and remove egg masses from belongings and adopt safe firewood practices. |
Here’s the takeaway: Don’t take it away!
Wood that looks clean and healthy can harbor tiny insects, eggs or microscopic fungi spores that can start a new and deadly infestation. Always leave your backyard firewood at home, even if you think it looks fine.
How to keep the fire burning
You can still have a roaring campfire or a cozy night in front of the fireplace if you just know how to burn safely.
- Aged or seasoned wood is not safe to move. Just because it is dry doesn’t mean it’s clean. A recent study showed insects continued to emerge from firewood even three years after it had been cut.
- Buy firewood near where you will burn it – a good rule of thumb is only using wood that was cut within 50 miles of where you’ll have your fire.
- Certified, heat-treated firewood is safe to move long distances. Look for a federal stamp or seal on the package, and keep the firewood in the original packaging if entering a campground that requires heat-treated wood.
- If you buy firewood and don’t burn it all, don’t bring it home or to your next destination.
- Tell your friends not to bring wood with them – everyone needs to know they should not move firewood.
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We’ve got a lot to protect
More than half of our state is forested – with an estimated 14 billion trees! Trees are part of every landscape we enjoy, from fall forest colors to river corridors to shady sidewalks and parks. Making safe firewood choices helps to protect the diversity and health of Michigan’s forest resources.
Learn more about protecting trees from invasive species at DontMoveFirewood.org.
Michigan’s Invasive Species Program is cooperatively implemented by the Department of Environment, Great Lakes, and Energy; the Department of Natural Resources; and the Department of Agriculture and Rural Development.
Note to editors: Accompanying photos are available below for download. Caption information follows.
- ALB larva: An Asian longhorned beetle pupa burrowed deep into the heartwood of a host tree. Photo courtesy of Pennsylvania Department of Conservation and Natural Resources, Bugwood.org.
- Magnification: Tiny hemlock woolly adelgids form round, white ovisacs are found on the undersides of hemlock branches near the base of the needles. Photo courtesy of Lorraine Graney, Bartlett Tree Experts, Bugwood.org.
- Egg masses: A gray, putty-like spotted lanternfly egg mass (center) just above a tan, fuzzy spongy moth egg mass on a tree trunk. Photo courtesy of Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org.
- Certified firewood: A certification stamp and the name and address of the firewood supplier should be visible on any certified firewood label. Photo courtesy of USACE.
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The Michigan Natural Resources Commission on Thursday enacted regulation changes on several inland trout lakes in the Upper Peninsula, effective Oct. 10, 2025. Four lakes have changed regulation types and four others have been removed from the list of designated trout lakes and no longer have a type designation. These changes will expand fishing opportunities for other species and better reflect the fish communities present in those waters.
With fire danger extremely high across much of Michigan’s Lower Peninsula today, firefighters are working near Houghton Lake in Roscommon County to contain a wildfire burning since Sunday afternoon, Oct. 5, near the Roscommon State Forest Area.
The DNR’s Outdoor Skills Academy and Becoming an Outdoors Woman programs offer opportunities to explore – and learn how to get started with – a variety of outdoor recreation activities. October classes include:
The Outdoor Adventure Center in Detroit has tons of fall fun queued up for October. Highlights include:
Delve into our state’s stories with these special programs at the Michigan History Museum in Lansing this month:
Several state parks in southern Michigan will host stewardship workdays, where volunteers are needed to help remove invasive plants that threaten high-quality ecosystems or to collect native wildflower seeds for replanting. Workdays will take place at:
If you’re an avid trail rider and looking to help maintain state-designated motorized trails, several off-road vehicle and snowmobile organizations across the state could use your help! Whether you have time to volunteer on a weekend or for a season, assistance is always appreciated.
Prescribed burns, timber harvests, tree planting and other activities are carefully planned to keep Michigan’s nearly 4 million acres of state forest thriving. Plans for these activities are currently being made for 2027, but public input is welcome now.
As the weather cools and the days shorten, the Michigan Department of Natural Resources continues the process of removing swim buoys and the Great Lakes flag system from many state park beaches.
