Chimney Fire! As someone who used firewood to heat my home for twenty years, I used to think that was all I had to worry about. Now I know how wrong I have been!
Firewood provides an avenue for forest diseases and insects to invade. Most of the insects that spread these diseases can move between 5 and 10 miles per year. With human assistance, though, they can move hundreds of miles a day—hitchhiking on firewood you transport in your vehicle!
Insect Pests in Western North Carolina
- Emerald Ash Borer (Agrilus planipennis—EAB) is a green beetle in the Buprestid family. It is native to north-eastern Asia and feeds on white ash (Fraxinus Americana) and green ash ( pennsylvanica) in WNC. Females lay eggs in bark crevices on the trees, and larvae feed underneath the bark of ash trees, emerging as adults in 1 to 2 years. First detected in Michigan in 2002, EAB spread northeast to Vermont, south to Georgia, and west to Missouri. The entire state of North Carolina is under USDA Animal Plant Health Inspection Service (APHIS) quarantine for EAB.
Emerald Ash Borer - Walnut Twig Beetles (Pityophthorus juglandia—WTB) are very small—1/16 inch (1.5 mm)—reddish-brown bark beetles in the Curculionid family. In NC, they attack black walnut (Juglans nigra), boring through the outer bark and into the phloem of trees’ branches and main stems. With the help of a fungus, Geosmithia morbida,they bring Thousand Cankers disease. In 2012, a Walnut Twig Beetle adult was captured in a trap in Haywood County.
Walnut Twig Beetle - Other insect pests under quarantine in North Carolina, but not in the Western region of the state, include European gypsy moth (Lymantria dispar), and the red imported fire ant (Solenopsis invicta).
What can YOU do?
- Respect any quarantine requirements regarding firewood movement.
- As of March 1, 2015, only heat-treated firewood bundled and certified by the USDA or a state agency may be brought into the Great Smokies Mountain National Park and the Blue Ridge Parkway. Campers may collect wood found in the park to use in campfires.
- If you have to move firewood over a long distance, make sure it is packaged, heat-treated firewood with a USDA APHIS heat treatment seal, or a state-based (such as a State Department of Agriculture) heat treatment seal.
- Burn any firewood you collect within a 50-mile radius of its origin.
- If you buy firewood and don’t burn it all, DO NOT take it home with you or to your next destination!
The use of firewood, a renewable resource, for heat has many advantages.
Firewood Basics
- Firewood is sold in what is commonly called a “cord”. This is defined in North Carolina as equal to the amount of cut and tightly stacked roundwood that can fit inside a container that measures 4 x 4 x 8 feet, or 128 cubic feet.
Split and stacked firewood - Cut AND split firewood typically reaches its driest state after 9 or more months, to include one summer. During this period, the wood should reach a moisture content of less than 20%.
- Stack firewood with the bark facing upwards to allow water to drain off, and any standing frost, ice, or snow off the wood surfaces.
- Be aware that storing wood close to a dwelling or inside for an extended period increases the likelihood that insects, such as termites, can become established indoors.
- Each species of wood has a different potential for providing heat. This is expressed in British Thermal Units (BTU).
Article by Bob Wardwell, Extension Master GardenerSM Volunteer
Invasive Species and Firewood Movement https://www.ncforestservice.gov/forest_health/pdf/5%204_WUI_CR_NNISandFirewood%20Movement_wNCFSLOGO.pdf
Preventing Firewood Movement https://www.ncforestservice.gov/forest_health/pdf/5%205_WUI_CR_PreventFirewood%20Movement_wNCFSLOGO.pdf
Comparison of firewood heating values
https://outreach.cnr.ncsu.edu/woodworkshops/documents/ChimneySweepsWoodBTUChart.pdf
More on Firewood Insects
https://outreach.cnr.ncsu.edu/woodworkshops/documents/FirewoodInsects.pdf