Black Locust Firewood

There's a running joke among firewood guys that black locust is the closest thing to coal that grows on a tree. I thought it was an exaggeration until I burned my first cord of it. Loaded the stove before bed, woke up eight hours later, and the coals were still hot enough to catch fresh kindling without a match. That never happens with most species. Black locust is in a league of its own for overnight burns.

At 23.2 million BTU per cord, black locust ties with sugar maple for one of the highest heat outputs among common eastern hardwoods. But it feels even hotter in practice because the 3,740 lbs of dry weight per cord is incredibly dense. The wood just radiates heat long after the flames die down. Green weight hits 4,616 lbs per cord, so yeah, hauling fresh rounds is a serious workout. Use the cord calculator to figure out volume before you load the truck, because you'll hit your weight limit well before the bed is full.

Splitting black locust is difficult and I won't pretend otherwise. The stuff is tough, stringy, and the grain fights you. Dry rounds are actually harder to split than green ones. Once black locust dries, it turns almost rock-hard. My advice: split it as soon as possible after cutting, while it's still green and has some give. A hydraulic splitter makes the job tolerable. Hand-splitting big rounds of dry locust... good luck.

You'll need 18 to 24 months of seasoning, which tracks for wood this dense. Black locust heartwood is naturally rot-resistant (people use it for fence posts that last 25+ years), so it holds up well while drying outdoors. Just split and stack it with airflow and be patient. The wait is absolutely worth it.

Black locust grows throughout the Northeast, Midwest, and Southeast, and once you know what it looks like, you'll start noticing it everywhere, it spreads aggressively. It's rated excellent overall, and compared to honey locust (which is good but not in the same tier), black locust is the clear winner for serious heating. Low smoke, few sparks, those legendary coals. If someone offers you black locust, don't even think about it, just say yes.