European walnut and American walnut - what are the differences between the two species

Walnut is a unique natural 'gem' and has long been appreciated for its versatility and aesthetic value. In the past, it replaced expensive mahogany brought from the colonies and because of its success, it has remained a favorite with carpenters and furniture recipients alike. What makes it special in appearance is the contrast of colors it flaunts. Its specific brown has a remarkable beauty, and the furniture does not need staining but only protection. But the natural color of walnut differs depending on where it comes from. The native walnut is lighter in color, unevenly colored, with yellow, green and reddish inserts, while the US walnut is dark brown, more uniform and with purplish tints. What other differences are there between the two species and how can they be identified? What is the nut's processing behavior and its uses, find out below.

Walnut - name, origins, distribution

Both species of walnut belong to the family JuglandaceaeThe family includes around 50 species of deciduous trees native to Europe, Asia and the Americas. All species have in common the production of different types of nuts, including our common walnuts and pecans. The name of the family comes from the Roman god Jupiter, who, according to legend, fed on walnuts throughout his earthly existence. The species best known as a source of wood are the English walnut (Juglans regia) and the American (Juglans nigra).

European walnutalso called English or common walnut, is a species that grows both cultivated and wild. It is protected and can only be felled with the approval of the Forestry Department, even if it grows in your own garden. In English you will find it under the names Persian walnut, English walnut, French walnut, Madeira walnut or common walnut. In French it is walnut or walnut treein Italian walnut or hickory, in Spanish walnut, European walnut or Spanish walnutand in German Nussbaum, Echte Walnuss or Baumnuss. It originates from the area stretching from the eastern Balkans to the Himalayas and south-west China, with Persia (today's Iran) being considered in many documents as the starting point. It was brought to Europe by the Romans and has been cultivated ever since.

American walnut, also known as the black walnut, is native to North America, growing mainly in the eastern US. In English you can find it as Black walnut or American black walnut, nBlack walnut or American walnut in French, black walnut in Italian, American black walnut in Spanish and Schwarznussbaum in German. Unlike the European walnut, which is grown all over the world for its nuts, the American walnut is grown primarily for its wood. The American walnut has also been grown in Europe for 200 years, brought over by English traders. It was also they who brought the European walnut, which is now grown extensively for nuts, to America. In fact, the US is the world's second largest producer, after China, which produces more than half of the world's total.

The first comparison between European and American walnut

The two trees, the European and the American walnut, are not very different in appearance. But there are some small differences that help to identify them. The European walnut grows to heights of 25-35 m, while the American walnut is taller and can exceed 40 m in height. However, the trunk of the European walnut is thicker, often reaching diameters of 1.5-2 m, while the American walnut is barely more than 1 m in diameter. The bark of the European walnut is green-brown and smooth when the tree is young, turning silvery gray and mottled when mature. The American walnut's bark is grayish-brown and heavily diamond-shaped. The crown of the European walnut is predominantly round, while the American walnut is elongated, with only solitary trees developing round crowns.

The leaves are similar and similarly arranged on the branch, but those of the American walnut are longer, narrower and more numerous. They have both female and male flowers that give rise to round, green-shelled fruits in the European walnut and green-brown in the American walnut, which open in late summer. The nuts fall off in the fall, and the loosened husk detaches from the nut. A hard horny shell remains to protect the kernel. This is very hard and darker in the American walnut, and there are hard walls inside that separate the kernel. European walnuts crack more easily, the kernels are lighter in color, can be pulled out whole and taste sweeter. American walnuts are very hard to crack, the kernels are broken out in small pieces, darker in color, astringent in taste and with a strong telluric flavor.

Main differences between European walnut and American walnut

Both species of walnut are valued in furniture production. There are many similarities in the appearance and behavior of the wood, but also differences that lead to the choice of one species over the other.

In cross-section the general appearance is similar, with distinct annual rings, semi-round pores, large and numerous in early wood, decreasing in size and number in late wood. The medullary rays, which give a natural gloss to walnut wood, are visible to the naked eye and normally spaced. The difference between sapwood and heartwood is clearly visible, with the sapwood very light, whitish, and the heartwood brown.

Differences between species occur especially in the color of the heartwood. In the European walnut the color is more uneven, varying from very light brown to almost black, with very different colored inserts, while in the American walnut the color is more uniform, dark brown with brownish and purplish iridescence. One could say that the main visual difference is the coloring, the distinctive shade palettes of the two species.

The fiber of the American walnut is generally straighter and more regular than that of the European walnut, which often has interesting designs formed by the uneven grain. European walnut is slightly finer than American walnut. Both species have knots, the fiber is irregular in those areas and more difficult to work.

European walnut is heavier than American walnut, with a density of 640 kg/m³ compared to 610 kg/m³ for American walnut. However, American walnut is more durable, more elastic and more resistant to abrasion than European walnut. As a result, American walnut will resist much better in damp environments (bathroom, kitchen) than European walnut. But both are equally susceptible to insect attack.

Being more elastic, American walnut can be steamed and bent more easily than European walnut, which tends to crack. Its durability, impressive stability and better abrasion resistance make it more suitable for flooring. This is not to say that European walnut is not good and its qualities are lacking, but that compared to American walnut its strength is lower.

Processing and uses

If the fiber is straight, both species of walnut are easily processed. During processing they give off a specific faint odor. Problems occur in the knot area or when the fiber is irregular. European walnut is easier to carve, American walnut is turn better. The American walnut can be bent by steam. Both species can be glued, colored and varnished without problems. Staining them is not recommended as the spectacular individuality of its natural color is lost. The best finish is oiled because it brings out the fiber and color very well. Tung oil is the most commonly used resulting in a silky, warm and smooth look.

Both species of wood are used to make furniture, veneer, various carved or turned objects or musical instruments. Walnut has been used to make rifle butts since the advent of the rifle, and is now commonly used to decorate luxury cars and yachts.

Walnut is one of the most versatile hardwood species to work with. Regardless of the walnut's origin, American or European, the wood that comes from this tree is renowned for its durability and overall dark color appearance. But this wood has a real appeal because up close, it has a real contrast of light and dark, making it particularly attractive.

I hope you find the above information useful. As always, additions are welcome. And if you have any questions or queries, please leave them below in the space provided. I will be sure to reply.

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