Is Black Locust Good Firewood? A Guide to Burning Black Locust for Heat - Backyard Boss
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Is Black Locust Good Firewood? A Guide to Burning Black Locust for Heat

Odds are, unless you’re really into wood, you’ve never heard of black locust or considered its value as a source of heat. If you’re looking for a heavy-heat, low-smoke type of firewood, though, Black Locust is your best option. While it’s not great for smoking the brisket for Fourth of July, it’s an incredible source of low-fragrance, high heat fuel for your home and cooking fires. Check out our guide below — we’ve gathered all the info you need to source, season, and burn Black Locust to its best use.

Black Locust Firewood Details

BTU: 27.5 to 29.8
Weight: 4650 wet 3900 dry
Seasoning Time: 1 year
Resin / Sap Content: Low to medium
Splitting Difficulty: easy
Smoke: low to medium
Smell: slight, pleasant

Black Locust Varieties

The Black Locust species is known all around the world. In the US, Europe, and China, the tree flourishes in nature. Here are a few details about popular Black Locust varieties (in alphabetic order):

endgrain and pores of black locust wood false acacia

Frisia Locust

A very tough variety of Locust is the oval-shaped Frisia Locust species. It has upward arching branches and white flowers when in bloom. In the summer, the leaves of the Frisia Locust turn crisp yellow and fade to gold in autumn.

Inermis Locust

The Inermis Locust is a much smaller version of the Locust tree. It rarely grows over 20ft tall and has a round globe-like shape.

Purple Robe Locust

A popular and compact variety of the Locust family is the Purple Robe Locust. It is easily one of the best looking types of Locust. The tree has gorgeous pink rose-like flowers and each year new growth branches appear bronze-red. That said, these Locust trees reach heights of up to 35 to 40ft in height. The downside to this beautiful Locust is that they don’t live as long as Black Locust and other Locust varieties.

Pyramidalis Locust

black locust (Robinia pseudoacacia) bark of black locust tree live
Black locust (Robinia pseudoacacia) bark pattern. Credit: Leslie J. Mehrhoff, University of Connecticut,

A tall species among Locust varieties, the Pyramidalis Locust reaches over 40ft high. The width of the tree reaches up to 15ft in diameter (which is huge!). The leaves of the tree are green during the summer and turn to yellow during autumn. The flowers of the Pyramidalis Locust bloom in clusters and are vivid white in color.


An odd Locust variety which is not much relied on for firewood is the strange-shaped Tortuosa Locust. This little tree reaches 15 to 20ft in height and has weirdly contorted sets of branches and gnarly tree trunk.


The Umbraculifera is another intriguing cultivar of Locust. The top of the tree has a flat and umbrella-shaped top. The species is rather uncommon in the United States but is more than common in Europe. The Umbraculifera makes a wonderful landscaping tree for yards and gardens.

Black Locust Firewood Burn Characteristics

BTU of Black Locust Firewood

Black Locust has an incredible BTU rating of nearly 30. That means that it burns hotter than many preferred firewoods. Black Locust burns longer than other types of wood as well. It also makes the most excellent coals.

Black Locust firewood is perfect for throwing into the fireplace for overnight burning. It will not only heat the home all night, it will provide enough coals and chard wood to easily stoke the fire back up the next morning.

bonfire place of fire

Firewood Seasoning Time

Technically speaking, Black Locust can be seasoned in as quickly as 6 to 8 months. But, if you want to properly season it for optimal use (higher BTU and longer burning time) then you need to season it for double that time. One year, to a year and a half, is the best seasoning time for Black Locust. That said, some folks claim that seasoning for 2 to 3 years is the best practice for seasoning Black Locust firewood for use indoors.

The natural moisture content level of Black Locust is between 26 and 28-percent or so. Before burning, you want to lower that moisture content to around 20-percent before using. Again, this is where proper seasoning time comes into play. Six months or more of seasoning should achieve a moisture content in Black Locust of 21-percent or lower. To reach the recommended 12-percent moisture content level, the wood needs extra seasoning.

Resin / Sap Content of Black Locust

Black locust moisture content levels measure out to around 25 to 26-percent. That means that it has no more resin or sap content than typical types of firewood. It also indicates that at least 6 months of seasoning is required to reach a suitable level of sap content (21-percent or lower).

Some Black Locust, however, produces higher levels of sap than others. For this reason, if you are harvesting Black Locust trees for firewood, the best time is in the autumn or winter when the moisture level is lower due to sap production slowing down for the season.

All things considered, Black Locust is excellent firewood to work with. Especially when seasoned properly, Black Locust has lower moisture content levels, burns hotter, burns longer, and creates great coals. It also has very little smell.

Black Locust Smoke and Smell

Black Locust is one of the best burning firewoods available in North America. When properly seasoned it puts off an enormous amount of heat (nearly 30 BTU) and precious little smoke. In fact, Black Locust smokes much less than other types of firewood popular with those who heat their homes with firewood.

Burning Black Locust has a faint woodsy smell (go and figure, right?), but is otherwise scentless. Unlike many popular types of firewood, like Cedar or Oak, Black Locust does not have a distinct smell. Most times, it is neither pleasant nor unpleasant. In other words, it is one of few firewoods that barely smokes or smells. This makes it more than ideal for use in heating your home.

woodburning fireplace indoors with feet resting on brick

When is the best time to cut Black Locust for firewood?

The best time to cut Black Locust, and indeed most types of firewood, is somewhere between winter and early spring. The reasoning behind this is that there is very little sap produced during these coldest parts of the year and the moisture content is therefore lower. That means when you cut the wood during these times that it dries out and seasons quicker.

How can I speed up the seasoning time of my Black Locust firewood?

You can speed up the seasoning process of your Black Locust firewood by stacking it several inches off of the ground (with pallets or a firewood rack). In addition, stacking the wood in an alternating pattern (one east to west, one north to south) allows for air pockets between each piece of wood. The clearance below, above, and between the firewood pieces makes for much quicker seasoning.

Is Black Locust Good for Smoking Meat?

No, Black Locust is not a preferable type of wood for smoking meat because it has little fragrance or flavor to transfer to meat.

black locust firewood smoked meat wide
Do your tri-tip a favor and choose a more flavorful wood for smoking. Good options include Oak, Mesquite, Hickory, Maple and Apple.

How long does a cord of Black Locust firewood last?

A properly seasoned cord of firewood will put off between 27 and 30 BTUs of heat. That means that the average amount of time a cord of Black Locust lasts is around 6 to 8 weeks. Granted, if you burn more or less wood than others, the time could be as little as 5 weeks and as much as 10 weeks.