Black Cottonwood

Populus trichocarpa · Hardwood · North America

Janka 350 lbf≈22 lb/ft³ dried (est.)

Properties

Janka hardness	350 lbf (1,557 N)
Average dried weight (est.)	22 lb/ft³ (350 kg/m³)
Specific gravity	0.35
Modulus of rupture	8,500 psi (58.6 MPa)
Modulus of elasticity	1.27 million psi (8.76 GPa)
Crushing strength	4,500 psi (31.0 MPa)
Shrinkage — radial	3.6%
Shrinkage — tangential	8.6%
Shrinkage — volumetric	12.4%
Shrinkage T/R ratio	2.4

Values at 12% moisture content, clear-wood averages. Source: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), Table 5–3b p. 5–9; shrinkage Table 4–3 p. 4–8.

Black cottonwood is the western member of the cottonwood group, growing along the West Coast and in western Montana, northern Idaho, and western Nevada. It is a light, relatively weak wood used mainly for boxes, crates, and pulp.

Appearance & grain

The heartwood is grayish white to light brown, and the whitish sapwood merges into it gradually. The texture is comparatively uniform, the grain is generally straight, and well-dried wood is odorless.

Workability

Cottonwood strength is moderately low and shrinkage is moderately high, and black cottonwood is slightly weaker than eastern cottonwood. Some cottonwood stock is difficult to work because tension wood leaves a fuzzy surface.