I lifted one split from the pile of black locust firewood cut along the back fence, and it dropped into my hand like a chunk of iron. That single log outweighed two splits of pine sitting next to it in the stack. I loaded a few into the stove before bed and damped the air down for the night. The next morning a deep bed of orange coals was still throwing heat into the room. So yes, black locust is one of the best firewoods you can burn. It runs hot, holds a long coal bed, and lights clean once it is seasoned all the way through.
The weight you feel in that log is the whole reason it burns so well. Black locust is one of the heaviest hardwoods that grows in North America. Dense wood packs more solid fuel into the same size split, and more fuel means more heat when it catches. That is why the black locust BTU rating sits near the top of every firewood chart. It gives off close to 28 million BTU per cord. That lands it among the hottest woods you can put in a stove. Cornell Small Farms ranks it with the highest-heat firewoods for this exact reason. All that stored energy also feeds a long, slow coal bed, so the fire keeps working long after the flames die down.
For firewood heat value, black locust runs shoulder to shoulder with oak and hickory, the two woods most people treat as the gold standard. It burns hotter than most oak and holds coals about as long as hickory does. There is one catch, and it comes straight from that density. Heavy wood dries slow. A fresh-cut locust split holds water deep in the core long after the outside turns gray and checked. Try to burn it too green and you fight a hissing, smoky fire all night.
Season it well and it pays you back every cold night. Split the rounds soon after you cut them, since smaller faces shed water faster than a whole log. Stack the splits off the ground with the top covered, and leave the sides open so air moves through the pile. Then wait. Give it a full year at a minimum, and two years if you can spare the space. Locust that has dried to 20% moisture or less lights with little fuss and burns clean. A cheap moisture meter from the hardware store settles any doubt before you load the stove.
This is a wood built for overnight heat in a closed stove. Load it on a bed of hot coals, cut the air back, and a few dense splits will hold a room warm until morning. One thing to know before you use it in an open fireplace. Black locust can pop and throw sparks as it burns, so a stove or a tight screen keeps stray embers off the floor. Inside a wood stove that spark never matters.
That fence the wood came from hints at another trait. Black locust resists rot better than almost any wood in the yard. That is why farmers used it for fence posts and watched them stand for decades. That toughness carries into the firebox. The dense grain that keeps a post sound in wet ground burns hot and steady once it is dry. The flip side is simple. The same density that fends off rot also makes the wood dry slow, so cut and split it early.
If you can get black locust firewood at a fair price, take all of it. Cut it, split it, and stack it now for next winter. Few woods give you this much heat per armload. Once it is dry, black locust burns as well as anything you can feed a stove.
Read the full article: Locust Tree: Honey vs Black Locust Guide
