Four Walnut Species – FineWoodworking

22 October 2026 Stan

There are 21 varieties of walnut trees worldwide, some more desired for their fruit, others for their wood. I’ll focus here on four. Eastern black walnut and claro walnut (or northern California walnut) are the most well known of all the walnuts, and furniture makers have been creating iconic pieces with their rich chocolate brown wood for centuries; these days their deep color and crotch figure have made them favorites for slab and river tables.

Peruvian walnut is an imported cousin that thrives in a more tropical climate, growing atop mountains in South America. Its wood is unmatched in the depth and richness of its color. Butternut, perhaps surprisingly, is also in the walnut family; its pale tan heartwood differs from the other walnuts, but it finds its place in many makers’ hands for its own beauty and workability.

All of them except butternut are sensitizers, meaning that over time some people can develop skin or lung irritations to the fine dust or wood. Hardwood prices have inflated considerably since the pandemic, none more so than those for eastern black and claro walnut. And the decline of butternut trees due to a rapidly spreading fungus has led to a sharp jump in cost as these trees shift from abundant to endangered.

But working any of these four walnuts with hand or power tools remains a joy. They may be in the same family, but they are very different, from coloration to weight and hardness, and each one makes a statement in its own way.

(Left to right) Eastern black walnut, claro walnut, Peruvian walnut, butternut.

Timber’s thumbprints

Vessel elements, more commonly referred to as pores, are strawlike tubes that transfer sap throughout a tree. Checking the end grain of a piece of wood to ascertain its pore structure helps identify tree types. Ring-porous woods have a defined line of large pores that form during the growing season. Semi-ring-porous woods, such as eastern black walnut, claro walnut, and butternut, have no defined line of pores but rather a gradually decreasing pore size from earlywood to latewood. Diffuse-porous woods, such as Peruvian walnut, have a consistent pore size and lack any differentiation from earlywood to latewood.

Janka scale

This measurement, used to determine the hardness of a wood, measures the pounds-force (lbf) required to embed a 0.444-in. steel ball halfway into wood that is dried to exactly 12% moisture content. Higher numbers correlate with harder wood, which is more resistant to wear, while softer woods register lower on the scale. For reference, basswood, one of the easiest-to-work woods, ranks at 410 lbf on the Janka scale, while white oak, a denser wood, ranks at 1,350 lbf.

Specific gravity

Another way to determine density, specific gravity measures with water instead of a steel ball. The scale uses 1.00 gram per cubic centimeter (the weight of water) as a baseline. Any wood measuring less than 1.00 will float on water; any wood measuring more will sink. For example, lignum vite, one of the densest woods, has a specific gravity of 1.26 and sinks like a rock. On the other end, balsa wood measures at 0.15 and floats almost completely on top of the water.

Forestry standards

As woodworkers we can choose whether or not to use endangered wood in our projects. The Forest Stewardship Council (FSC) certifies wood that has been cut from sustainable forests or plots in an environmentally responsible way. The International Union for Conservation of Nature (IUCN) has created a Red List of species that are extinct, in danger of becoming extinct within three generations, or of little concern of becoming extinct. This helps governments form policies and restrictions to keep species alive.

Movement

Measuring the percentage of movement of a piece of wood transitioning from its green-wood state to its driest form is a great way to determine its stability in changing climates. This is more commonly noted as wood movement and is something to take into account with design. To give a baseline, cherry shrinks 3.7% radially and 7.1% tangentially, and eastern white pine shrinks 2.1% radially and 6.1% tangentially.

Eastern black walnut (Juglans nigra) – a famous familiar

illustration of black walnut leaves and seeds

illustration of region in the US where eastern black walnut trees are found

Found across the Midwest, Southeast, and Appalachian regions of the United States, eastern black walnut is the most abundant walnut species. The most commercially sought-after trees with clear grain and beautiful color are grown in the woods of Indiana, Iowa, and Missouri.

These large trees are coveted by veneer manufacturers for their straight grain. Sawmills typically steam the walnut slabs before they go into the kiln in the hope of homogenizing the light sapwood with the dark heartwood. This allows the wood to be graded higher, resulting in more profits for sawmills.

Urban trees with poor shapes and lower limbs produce perfectly imperfect wood for slab furniture makers. Often air-dried, this wood retains a stark contrast between the light cream-colored sapwood and rich brown, almost purple, heartwood. Because of the price of walnut lumber, some landowners have converted fields into walnut groves in the Midwest, hoping for a windfall when the trees mature and are harvested.

Growing region: Southeast, Midwest, Appalachia
Size: 130 ft. tall, 6 ft. dia.
Identifying features: Semi-ring porous
Price: $6 to $15 per bd. ft.
Density (Janka scale): 1,010 lbf
Specific gravity: 0.55 at 12% moisture content
Movement: 5.5% radial and 7.8% tangential
Forestry standards: Least concern IUCN Red List; not FSC-certified

The Conoid Bench. It’s nearly impossible to see a black walnut slab and not have an image of a furniture piece by George Nakashima flash in your head. Nakashima’s use of the entire slab displays the wood’s true character and beauty by bringing attention to perceived imperfections such as checks and sapwood.

Claro walnut (Juglans hindsii) – California’s treasured gem

illustration showing region where claro walnuts grow in the us

Growing only in northern California, claro walnut differs just slightly from its more abundant cousin, eastern black walnut, although price can often be a clear indicator, with claro walnut being double the cost nationwide.

Its heartwood is a dark chocolate brown with streaks of varying shades, creating a beautiful array of color throughout. Claro walnut is used as rootstock for English walnut trees grown in California for their fruit. The hearty root system is ideal for growing in the tougher soils of northern California so the grafted English walnut can flourish.

When grafted onto a claro tree, these Californian English walnut trees often produce burls and stunning figure, which are used for veneer and bowls. Luminary furniture maker Sam Maloof, a native Californian, used claro walnut for many of his famous chairs. Although the differences are subtle, claro walnut stands on its own as the premium walnut grown in the United States.

Growing region: Northern California
Size: 100 ft. tall, 6 ft. dia.
Identifying features: Semi–ring porous
Price: $6 to $15 per bd. ft.
Density (Janka scale): 1,130 lbf
Specific gravity: 0.64 at 12% moisture content
Movement: 4.3% radial and 6.4% tangential
Forestry standards: Least concern IUCN Red List; not FSC-certified

Arts and Crafts bed. Like the claro walnut trees he works with, Michael Cullen grew up in California. Sourcing his trees straight from the local sawyers, Cullen admires the beautiful movement in the wood, which he has dubbed “quasar grain.”A nightstand of dreams. Cullen’s nightstands, mates of the bed above, were made from a single plank of claro. Their straight grain counters the figure and movement of the claro boards he used for the bed.

Peruvian walnut (Juglans neotropica) – South America’s mountaintop beauty

illustration of region in south america where peruvian walnut trees grow

Although the name suggests that it’s grown only in Peru, this walnut grows throughout Latin America, including Ecuador, Colombia, Venezuela, and even parts of Mexico. In contrast to their northern cousins, Peruvian walnut trees thrive in a high-humidity, high-altitude environment. The heartwood is a rich chocolate brown, darker than that of domestic walnut, with occasional white streaks.

The sapwood is smaller than that of domestic walnut trees. Peruvian walnut is listed as endangered on the IUCN Red List. As with other South American trees of value, a lack of regulations on harvesting has led to the quick decline in old-growth Peruvian walnut trees.

The wood’s large pores are distributed equally across its growth rings, making it diffuse porous, unlike the other walnuts, which are semi–ring porous. It is because the trees grow in a environment with mild seasonal dormancy that there isn’t as clear a delineation between the earlywood and the latewood as in other walnut species. Peruvian walnut’s diffuse pores give its wood the depth and richness that make it stand out.

Growing region: South America
Size: 60 ft. tall, 3 ft. dia.
Identifying features: Diffuse porous
Price: $12 to $20 per bd. ft.
Density (Janka scale): 960 lbf
Specific gravity: 0.6 at 12% moisture content
Movement: 3.6% radial and 7.5% tangential
Forestry standards: Endangered IUCN Red List; some FSC-certified

peruvian walnut chest of drawers by dan bollock

A case for contrast. Dan Bollock’s chest of drawers puts Peruvian walnut on display. The case, constructed of the South American cousin, creates a perimeter of rich chocolate brown around the pastel-painted drawers.

Butternut (Juglans cinerea) – the softer side of walnut

illustration shows region of the US were butternut walnut trees grow

I consider butternut to be the crazy uncle in the walnut family. It is tan with a slight reddish-orange cast and occasional darker streaks. Because of its lighter heartwood, it is sometimes called white walnut. Butternut is less dense than all the other walnuts, making it unsuitable for high-wear projects like tabletops or gunstocks. But less dense isn’t necessarily a bad thing. Butternut is incredibly workable and is an absolute pleasure to hand plane.

Butternut grows in a similar range to that of eastern black walnut, just shifted a little north and east. Since the butternut canker entered U.S. forests in the 1970s, the population of butternut trees has decreased by approximately 90%. This fungus enters through cracks in the bark and attacks the cambium layer of the tree, which is why butternut is listed as endangered on the IUCN Red List.

Growing region: Midwest, Northeast, northern Appalachia
Size: 70 ft. tall, 2 ft. dia.
Identifying features: Semi–ring porous
Price: $5 to $30 per bd. ft.
Density (Janka scale): 490 lbf
Specific gravity: 0.43 at 12% moisture content
Movement: 3.4% radial and 6.4% tangential
Forestry standards: Endangered IUCN Red List; not FSC-certifiedSubtle beauty. This low dresser by Michael Pekovich is a master class in using butternut. Less audacious than the other walnuts, butternut blends with more neutral materials instead of contrasting with them. Pekovich’s use of oak in the structural parts and butternut for the panels and drawer fronts speaks to his knowledge of the softer, subtler wood.Practically perfect. Pekovich’s choice of butternut for this tool chest was a practical one: A box full of heavy things should be as light as possible. In addition to being remarkably lightweight, butternut boasts beautiful figure.