Yes—black locust is an excellent firewood for heat when it is properly seasoned. Extension tables put it at roughly 27–28 million BTUs per cord, though one source gives a wider range. Its main drawbacks are that it can be hard to split and difficult to start. Check moisture instead of relying on appearance or a fixed seasoning schedule.
How much heat does black locust produce?
Black locust ranks among the higher-heat firewoods in the cited extension tables. University of Illinois Extension lists 28.1 million BTUs per cord; Oklahoma State University Extension gives a range of 23.2–28.3 million BTUs per cord for dry black locust; and the University of Arkansas Division of Agriculture Cooperative Extension Service lists 27 million BTUs per cord. These are reference estimates, not guaranteed output for every cord. Moisture and the basis used for each table affect the figures.
These values are per cord, not per log or per pound. Dense hardwoods put more dry wood—and therefore more potential heat—into a given cord volume. Illinois Extension notes that wood species produce similar heat per unit of dry weight; the difference in heat per cord largely reflects how much dry wood fits in that volume. University of Illinois Extension: Firewood
What are the trade-offs?
| Characteristic | What the extension sources report |
|---|---|
| Heat per cord | Illinois: 28.1 million BTUs; Oklahoma State: 23.2–28.3 million BTUs for dry wood; Arkansas: 27 million BTUs. These are source-specific estimates. |
| Splitting | Arkansas rates black locust difficult to split. |
| Starting | Illinois describes it as difficult to start; Oklahoma State recommends using less-dense, smaller fuels to establish a fire. |
| Sparks and smoke | Illinois reports few sparks. Arkansas rates it as producing few sparks and low smoke. |
| Coaling and overall quality | Arkansas rates its coaling and overall firewood quality excellent. |
The ratings describe general characteristics, not a guarantee for every piece or appliance. Arkansas says its figures were compiled from USDA Forest Service Leaflet No. 559. See the Illinois Extension firewood guidance, Oklahoma State Extension recommendations, and Arkansas Extension firewood table.
Free tools Windows power users keep installed
One-click scans. No signup required.
#1 Best Overall
- BEAUTIFUL BLACK LOCUST: It's fragrant white flowers are beloved by bees. Attractive wood is popular as lumber.
- EASY TO GROW: Growing instructions included. Seeds come ready to plant.
- FAST-GROWING HARDWOOD TREE: Establishes quickly and develops height faster than many hardwood species. Suitable for long-term planting where early growth is important.
- FRAGRANT SPRING FLOWERS: Produces white, pea-like flowers in hanging clusters during late spring, typically May to early June. Blooms are short-lived but noticeable and attract pollinators.
- ROT-RESISTANT WOOD: Produces dense hardwood known for natural resistance to decay. Commonly used for fence posts, outdoor structures, and other ground-contact applications.
How to prepare and burn black locust
Split and stack it
Because black locust can be difficult to split, work with manageable pieces and use a splitting maul or mechanical splitter if appropriate for your logs and ability. These are options, not a guarantee that every piece will split easily. Stack the wood in a dry, well-ventilated location so air can circulate.
Build the fire gradually
Start with dry kindling and smaller fuel, then add larger black locust pieces once the fire is established. Oklahoma State Extension recommends smaller, less-dense fuels for starting a fire; black locust’s high density can make it less cooperative as the initial fuel.
Rank #2
- BEAUTIFUL BLACK LOCUST: It's fragrant white flowers are beloved by bees. Attractive wood is popular as lumber.
- EASY TO GROW: Growing instructions included. Seeds come ready to plant.
- FAST-GROWING HARDWOOD TREE: Establishes quickly and develops height faster than many hardwood species. Suitable for long-term planting where early growth is important.
- SEED POD DEVELOPMENT: After flowering, flat seed pods form and mature through summer, typically 2–4 inches long. Pods dry and release seeds naturally in fall.
- COLD HARDY AND ADAPTABLE: Hardy in USDA Zones 4–8 and tolerates a range of soil types, including lower fertility soils. Performs best in full sun with well-draining conditions.
Season it, then verify moisture
University of New Hampshire Extension says indoor firewood should be seasoned for 6–12 months and burned at 20 percent moisture or less. The time needed depends on drying conditions, so months in a stack are not proof that wood is ready. A moisture meter is the most reliable practical check described by UNH Extension:
- Split a log to expose a fresh interior face.
- Press the meter pins into that freshly split surface and read the result.
- Test multiple pieces from different parts of the stack to get a more useful picture than a single reading.
End checks and a ringing sound when dry pieces are struck can offer clues, but they do not replace a moisture-meter reading. See UNH Extension’s seasoning and moisture guidance.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Rank #3
- FAST-GROWING NATIVE TREE: Black locust (Robinia pseudoacacia) is a fast-growing North American tree that establishes quickly and adapts to a wide range of environments, making it useful for long-term planting projects.
- FAST GROWING TREE SPECIES: Known for relatively rapid growth compared to many hardwood trees. Establishes quickly and begins developing height early in its lifecycle.
- DURABLE, ROT-RESISTANT WOOD: Produces dense hardwood naturally resistant to decay, making it historically used for fence posts, outdoor structures, and ground-contact applications.
- MATURE SIZE AND STRUCTURE: Trees can reach 30–70 feet tall with a spread of 20–35 feet at maturity. Develops an open canopy with compound leaves.
- SUITABLE FOR FIREWOOD: Wood burns hot and long when properly seasoned, making it a practical option for firewood use compared to many other hardwood species.
Burn it safely
Burn dry, seasoned wood. Wetter wood burns less completely and at a cooler temperature, producing more smoke and less useful heat while contributing to creosote buildup in the chimney. Creosote is a fire hazard. Follow the appliance manufacturer’s instructions and local fire guidance, and maintain the appliance and chimney regularly. For an open fireplace, use a screen to help keep sparks from landing on combustible materials. Illinois Extension’s firewood burning-safety guidance and UNH Extension explain the risks of burning damp wood.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
