Black Walnut as firewood- Is Black Walnut Firewood Good for Anything?

Are you looking for firewood with near excellent heat production, is easy to split, and has a sweet aroma upon burning? Look no further than the Black Walnut tree. We know walnuts for their delicious nuts and high protein content. But can we use Black walnut as firewood? Of course, yes. Join us as we delve deeper into the critical properties of black walnut firewood. 

What is Black Walnut Firewood?

A couple leans on a Walnut Tree.

A couple leans on a Walnut Tree.

The Walnut tree is a hardwood tree native to North America. It is renowned for its hard-shelled fruits that are a great addition to desserts. 

But the Walnut tree also makes top-quality firewood. Its general features are as follows:

  1. First, it yields a sweet aroma while burning, and its BTU rating ( 22.2 million) is relatively within the range of top firewood trees. 
  2. Besides, it weighs approximately 1447.86685 kgs per dry cord and takes a relatively short time to season entirely (6 months to 2 years). 
  3. Lastly, you can effortlessly split Black Walnut firewood, which yields relatively low smoke when burning, thus ideal for indoor firepits. 

Burn Qualities of Black Walnut Firewood

A Walnut tree board

A Walnut tree board

Here are the specific burn qualities of black walnut firewood. 

a.) Heat Production

Black Walnut is a Good Firewood Tree.

The Black Walnut is a Good Firewood Tree.

Black Walnut’s heat production doesn’t match that of renowned hardwood trees like oak. Black Walnut has excellent heat production at 22.2 million BTUs compared to other trees such as alder or pine. 

So good is the heat output of Walnut coal that one cord yields heat equivalent to 874.43 liters of propane gas or 20, 347  ft3 of natural gas

b.) Smoke Production

Black Walnut firewood produces limited smoke. 

Black Walnut firewood produces limited smoke. 

Black Walnut has limited smoke output, especially if you allow sufficient seasoning. Also, it barely produces sparks while burning, thus ideal for indoor woodstoves and fireplaces. 

But you must know that Black Walnut firewood will burn faster than conventional hardwoods such as oak. Therefore, consider mixing it with hardwood with a higher BTU, like oak, for an extended burn time. 

c.) Seasoning period

Black Walnut takes about 2 years to season fully. 

Black Walnut takes about 2 years to season fully. 

On average, Black Walnut firewood will take between 1.5 and 2 years to season thoroughly. However, it can dry less quickly with sufficient sunlight and ambient heat. You can know when your Black Walnut firewood is thoroughly dried by checking for the presence of cracks and a significant drop in its weight. 

Also noteworthy, the Black Walnut firewood is lowly rated compared to other firewood trees regarding its ease of drying. 

d.) Burning Smell

Black Walnut burns with a sweet smell.

Black Walnut burns with a sweet smell.

One of the outstanding features of firewood for fireplaces is the production of a sweet aroma when burning. The Black Walnut tree perfectly ticks this box as it’s sweet smelling. 

e.) Creosote Buildup

Black Walnuts have low creosote. 

Black Walnut is low creosote firewood. Additionally, Black Walnut firewood has moderate sap at 8 -14 percent. Sap contributes to smoke production; thus, the lower the value, the better the wood’s burn quality. You can significantly limit sap production by ensuring your firewood is well-dried. But, as a general rule, you must regularly clean your chimney and woodstove to prevent creosote buildup.  

f.) Ease of Splitting

Because of its medium-density grains, you must fully allow your Black Walnut firewood to dry for easy splitting with an axe

But, you will find it easy to break Black Walnut trees that grow en masse in a dense forest. Such trees compete for sunlight and thus tend to elongate, forming limited knots and less twisted grains. 

Different Species of Walnut

Green Walnut Fruits

Green Walnut Fruits

There are many walnut varieties growing in the world. They include the following: 

But you’ll find only the three main types below in the US. 

i.) English Walnut 

Other names of this Walnut species include the Madeira walnut, Persian walnut, and Carpathian walnut. The tree was indigenous to Iran, although today, it is popular in California, US. 

It’s a fast-growing tree species and attains full maturity at 60 years (Growth height of 40 to 60 ft). 

You can identify this Walnut species via its olive-colored bark while its tender age. However, the bark color changes to grey upon maturity and may also develop fissures. 

ii.) White Walnut or Butternut 

It is renowned for its rot-resistant lumber. Other remarkable characteristics of the White Walnut are as follows: 

  1. It is a water-intensive tree that grows best along river banks and well-drained soils. 
  2. Secondly, it attains maturity in 75 years, longer than the English Walnut but shorter than the Black Walnut. 
  3. It also features a course grain system making it ideal lumber for woodworking applications. 
  4. Further, it has a smooth and gray bark while young, but the stem develops fissures once the tree matures. 
  5. Also, the tree has an oval-shaped trunk rather than the round one, which is synonymous with most trees. 

iii.) Black Walnut

A Black Walnut Tree

Our featured Walnut tree (the Black Walnut) can live up to 200 years and can get up to 150 feet in height. Its key features include the following: 

  1. They have excellent lumber, which has rendered the trees extinct in the wild. 
  2. Also, they have hard nuts that are delicious. The protein content of its nuts is arguably the highest of all trees. 
  3. Thirdly, the trees will do well on well-drained soils and areas with sufficient sunlight. 
  4. Their bark color for mature trees ranges from gray to brown. The bark also features relatively deep ridges compared to other Walnuts. 
  5. Lastly, the trees are renowned for producing a toxic chemical that repels other plants. Hence, you’re unlikely to find any vegetation within a 50-80 ft radius of the Black Walnut tree. 

Identifying Walnut Trees

A Black Walnut tree

A Black Walnut tree

We can identify the Black Walnut from other trees by the following features: 

Black Walnut Leaves

Black Walnuts are renowned for their compound leaves with approximately 5 to 25 leaflets. Further, its leaves will give a spicy citrus extract. Lastly, its leaflets are round, and often, you find the terminal leaflet missing. 

Also, it is deciduous, so its leaflets will brown and fall off in the fall season.  

Black Walnut Nuts

Black Walnut Nuts

Walnut nuts are green and round. But this green outer cover houses a hard shell enclosing a highly proteinous nut. 

Black Walnut Bark

Black Walnut Bark

The tree has grey bark with deep ridges. However, it can also change to brown and sometimes forms diamond-like patterns. Lastly, you may also come across Black Walnuts with a smooth and light grey bark though this is a rarity. 

How Black Walnut Compares to Other Woods

The table below shows how Black Walnut firewood quality compares to other wood species. 

Firewood TreeBTU ratingEase of SplittingCoals QualityOverall Wood Quality
Maple25.5Easy Excellent Excellent 
Black Walnut22.2Easy Good Excellent
Osage Orange32EasyExcellent Excellent
Green Ash20.0EasyGood Excellent
Bur Oak26.2EasyGoodExcellent


Black Walnut is a hardwood best renowned for its excellent lumber qualities. However, we can also regard the Black Walnut as among the top firewood trees. For more information on Black Walnut firewood, contact us at any time.