Choosing Firewood
With winter approaching, now may be the time that many are looking to restock firewood for the season. Though outwardly straightforward, some science behind this task can assist people in choosing the correct wood. Not all wood is equal. As such, tree species differ in the heat they produce when burned. So, which trees are best for firewood, and which should be avoided?
Variations in heat emission can largely be accredited to wood thickness. Hardwood has incredibly compact fibers, making it take longer for fire to cut through. In turn, this results in the wood burning hotter. However, this is not to say that all hardwoods are your answer. Cutting Black locust, a noted hardwood, logs, is significantly easier said than done. Just as fire has trouble carving through the wood, a chainsaw and a log splitter also have trouble. Hardwood boasts the dual feature of producing the most heat and saving money while easily breaking equipment and losing money.
Then, there is the matter of whether the wood is safe. Osage Orange is plentiful near Kansas City, which should be a blessing since it is one of the hottest-burning, most dense woods that exist, but you would never want to burn it in an open fireplace. The wood contains pockets of resin that explode when it burns, causing sparks to erupt from your fire. It may even burn too hot for a typical fireplace, melting it if it isn’t properly equipped.
BTU charts, which show the heat a wood burns at in British Thermal Units, are a great place to get an idea of which wood you should aim for when choosing firewood. The higher the BTU, the better the heat-generating capability of the wood. But before settling on a choice, it needs to be remembered that several woods have caveats.
We know Osage Orange is dangerous and that Black Locust is hard on equipment, but did you know that Honeylocust will also spark? Siberian Elm, American Elm, and Sycamore could also be difficult to split because they have uncooperative wood grain. Other woods to avoid are Catalpa, Cottonwood, or Willow because the fibers of these trees are less dense and emit significantly less heat. Cedars, Lindens, and several Pines emit even less heat than a Willow due to their softness –so being finicky in selection can be beneficial. On the other end of the spectrum, if Hickory, Pecan, Mulberry, Bur Oak, or Red Oak can be located, these would all produce decent amounts of heat without some of the adverse side effects others may have.
It is highly recommended within the Kansas City area that firewood is not transported far from the area where it was grown, sourcing it within your home county. By doing so, you play a crucial role in preventing the spread of tree diseases and pests, which could devastate your local environment. Emerald ash borer, pinewood nematode, and Dutch Elm Disease are all major horticultural issues that are heavily instigated by firewood transport. So, play it smart. Source your firewood locally, and ensure it is suitable wood with the correct features for the job.
by Anthony Reardon, Horticulture Small Farms Agent 2024