Walnut

Species Detail

The Basics

Walnut is one of the most sought-after species in markets across the world and is unique to North America.

The sapwood of walnut is creamy white, whereas the heartwood is light brown to dark chocolate brown, making the difference in color quite distinct. Occasionally the heartwood has dark, even purple, streaks. The wood of walnut is generally straight grained, although sometimes with wavy or curly grain that produces its characteristic and attractive figure, sought after by designers.

Scientific Name

Juglans nigra

Also Known As

Black Walnut

Avg. Board Length

Avg. Dried Weight

3.2 lbs/bdft

6’ – 12’

4” – 8”

4/4, 5/4, 6/4, 8/4, 10/4

Avg. Board Width

Common Thicknesses

Species

Overview

Where It Comes From

Growth

Distribution

Walnut trees grow very widely across the eastern USA in mixed hardwood forests and on farms, concentrated in central states but spread from Texas to the eastern seaboard. The trees are one of the few hardwood species planted as well as occurring and regenerated naturally. They grow relatively tall and straight with few lower branches.

FIA data shows U.S. walnut growing stock is 137.8 million m3, 0.9% of total U.S. hardwood growing stock. American walnut is growing 4.8 million m3 per year while the harvest is 1.9 million m3 per year. The net volume (after harvest) is increasing 2.9 million m3 each year. U.S. walnut growth exceeds harvest in all major supplying states except Michigan.

Walnut from the USA is available as sawn lumber and as veneer. The lumber is generally sold un-steamed and unselected for colour. Specialist producers may offer steamed walnut intended to darken the sapwood and thus reduce the colour difference between heartwood and sapwood. Recent years have seen huge global demand for this species. NHLA Grading Rules are modified for walnut, allowing smaller specifications and smaller clear cuttings and sapwood is admitted without limit. Consultation with suppliers is recommended.

0-4K

4-8K

8-12K

12-16K

16-20K

20-24K

Volume of live trees on forest land, 1000 m³

Uses

Common

Applications

Walnut is considered one of the supreme species for high end furniture, cabinets, doors and interior joinery. It is used for flooring and panelling and it is widely used to contrast with other hardwoods.

Hardwood flooring and book shelves in a library made from Walnut.

Finishes

Finding the

Right Finish

Species Variations

Vibrance in

Variation

Walnut lumber can be processed either as steamed or unsteamed, impacting its color uniformity and workability. Steamed walnut is treated with heat and moisture to darken its naturally lighter sapwood, creating a more uniform color throughout the wood. This process also makes the walnut slightly softer and easier to work with. Unsteamed walnut, on the other hand, retains the natural contrast between the darker heartwood and the lighter sapwood, offering a more distinct, varied appearance. Both methods have their unique aesthetic appeals and practical applications, depending on the desired finish and use of the wood in projects.