Is Burning Walnut Wood Toxic?

When you think of Walnut trees, you’re likely to call to mind the delicious nuts they produce. However, Walnut trees offer more than just tasty snacks; they can also serve as an excellent source of firewood for your fireplace. While living Black Walnut trees can be toxic to plants attempting to grow under and around them, the wood from these trees is not at all toxic to burn.

In fact, Walnut wood is a very good choice for firewood for several reasons. It’s a good hard wood that burns clean and gives off quite a bit of heat along with a pleasant aroma. As an added bonus, Walnut is fairly easy to split. If you’re fortunate enough to have Walnut trees nearby, you’d be smart to consider taking advantage of this valuable firewood resource.

Common Varieties of Walnut Trees Used for Firewood

Common Varieties of Walnut Trees Used for Firewood

There are about twenty different types of Walnut trees worldwide, but only two are commonly grown and harvested in the United States. Both make fine choices as firewood.

Black Walnut trees produce both tasty nuts and valuable lumber. These trees are primarily found in the eastern United States, extending as far west as Nebraska, Kansas, and Texas.

They grow best in deep, rich, and moist yet well-drained soil. This means that they need regular rainfall or irrigation, but they cannot stand in water for extended periods of time. Excess amounts of water must be able to run off freely.

Black Walnuts have a bold, earthy flavor, with thick shells that can be challenging to crack and may stain your hands. This is why they are most commonly grown for lumber, but don’t discount the value of the nuts.

They are well worth the effort it takes to harvest and prepare them, both because of their rich taste and because they can be sold for a tidy profit if you so desire.

Black Walnut trees are rather slow-growing and may take as long as 150 years to fully mature. These trees grow to be about 65to 100 feet tall and can live for 250 years.

For these reasons, growing them for firewood might be difficult as they simply would not grow fast enough for you to harvest much firewood.

Large, old trees that need to be removed may yield excellent wood for arts, crafts and furniture making, or of course, you could burn it if you wanted.

Mature Black Walnut trees that have been damaged by inclement weather might be better suited to use as firewood.

English or Persian Walnut trees are widely cultivated in California. They produce nuts that are easier to process and have a milder flavor than Black Walnuts.

These trees are fairly fast-growing and can rapidly attain heights of 40 to 50 feet, so growing them for firewood is doable. Life expectancy for an English or Persian Walnut tree is about 60 years.

Walnut Firewood & Slab Wood

Walnut Firewood Q&A

What does Walnut firewood smell like?

The rich scent of burning Walnut wood is nutty and earthy. This pleasant aroma is one of Walnut firewood’s most notable characteristics, adding to the ambiance of heating your home with wood.

Is Walnut sap messy to deal with?

Compared to Pine trees, Walnut trees are relatively clean. While cutting Pine can lead to sticky sap covering your gloves, work clothes, shoes, and chainsaw, Walnut sap is less of a hassle.

In fact, another good use for mature Black Walnut trees is sap production. These trees can be tapped, just like maple trees, and produce a light, tasty syrup.

Is it hard to split Walnut firewood?

Walnut wood generally splits easily, except when dealing with forked or knotty trees. If you must split your wood by hand, you can use this method:

…or if you have heavy duty log splitting equipment, try this!

How long does it take to season Walnut firewood?

Firewood should ideally have a moisture content below 20 percent for efficient burning. As with all hardwoods, Walnut needs to season for about a year after being split to reduce moisture content. Good, dry hardwood will provide the best burning and heating.

Is Walnut a clean-burning wood?

Any firewood will generate some creosote, but properly seasoned Walnut wood burns relatively cleanly, with minimal smoke and sparks.

Be aware that, no matter what kind of wood you burn, creosote can accumulate in the chimney and pose a fire hazard. Properly seasoning Walnut wood before burning can help reduce creosote buildup.

Be sure to check and clean your chimney on a regular basis. It’s also important to keep your fireplace clean for safety and efficient burning. Some people do say that Walnut produces quite a bit of ash because it burns quickly.

Should you combine Walnut with other types of firewood?

Walnut is a hardwood and may not burn as long as Oak or Pine. For this reason, combining Walnut firewood with oak and/or pin is a great way to build an excellent, long-lasting fire.

Is Walnut better than other kinds of firewood?

Walnut is a medium-density wood that burns easily. It is not quite as efficient as oak firewood, but it is much more efficient than softwoods, such as cedar.

In terms of BTUs per cord, Walnut falls in the middle range. Eucalyptus and Osage-Orange are most efficient and have higher BTU values.

Ohio Buckeye and Linden Basswood are less efficient and have lower BTUs per cord. Walnut firewood falls squarely between these other choices.

Is it easy to find Walnut firewood?

Availability varies across the United States, as well as in Southern Canada. Natural stands are more concentrated in the mid-west and Eastern US. Native Black Walnut trees can be found alongside streams, on north and east facing slopes and at forests’ edge in most states, such as:

  • North Carolina
  • New Jersey
  • Oklahoma
  • Alabama
  • Kansas

…and more.

There are also large commercial orchards to be found in California. Commercially grown Walnut can also be found in:

  • Minnesota
  • Missouri
  • Indiana
  • Illinois
  • Iowa

Trees grown in a stand tend to have tall, straight trunks, resulting in better-quality wood compared to those growing in open areas, which often develop large canopies.

Is it better to harvest or purchase Walnut firewood?

Of course, you must never take naturally growing wood of any sort from private or public lands without permission, and you may find that growing Black Walnut trees as firewood is a very slow process. These trees only grow one or two feet a year.

Another downside to harvesting Walnut firewood from the woods is that moving wood from one setting to another can spread diseases that affect Walnut and other trees.

Commercially grown trees are less likely to carry pests, viruses and/or fungal or bacterial infections.

For these reasons, you may find commercially sourced Walnut firewood is your best bet.

Heat Output and Efficiency of Walnut Firewood vs. Other Heating Fuels

Depending on the species, Walnut wood produces between 20.0 to 22.2 million BTUs per cord. To put this in perspective, a cord of Walnut is roughly equivalent to:

  • 6,184 kilowatt hours of electricity.
  • 20,347 cubic feet of natural gas.
  • 152 gallons of heating oil.
  • 231 gallons of propane.

A cord of firewood equals 128 cubic feet of wood, typically cut into 16-inch lengths and stacked tightly in three rows measuring 4 feet high and 8 feet long.

Walnut Firewood: Ignite Comfort & Efficiency in Your Home

It’s easy to see that Walnut wood can be a very good choice for firewood, thanks to its clean-burning properties, pleasant scent, and ease of ignition. While it may not match the heat output of some hardwoods, it far outperforms softwoods.

Combining several types of firewood is an excellent way to build a long-lasting, toasty fire.

Just remember to provide a proper seasoning time for Walnut, and all types of firewood, for the very best results when heating with wood.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Farm & Animals

6043 S Drexel Ave
Chicago, IL 60637

Amazon Disclaimer

Farm & Animals is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to


Farm & Animals do not intend to provide veterinary advice. We try to help farmers better understand their animals; however, the content on this blog is not a substitute for veterinary guidance. For more information, please read our PRIVACY POLICY.