Quaking aspen (Populus tremuloides) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Quaking aspen |
|---|---|
| Janka side hardness, 12% moisture | 350 lbf (1,557 N) |
| Janka side hardness, green | 300 lbf |
| Hardness rank | harder than 2 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 26.6 lb/ft³ (426 kg/m³) |
| Weight per board foot (12%) | 2.21 lb |
| Specific gravity (ovendry weight, green volume) | 0.35 |
| Specific gravity at 12% moisture | 0.38 |
| Bending strength (modulus of rupture), 12% | 8,400 psi |
| Stiffness (modulus of elasticity), 12% | 1.18 million psi |
| Crushing strength (compression parallel to grain), 12% | 4,250 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 3.5% / 6.7% / 11.5% |
| Tangential / radial shrinkage ratio | 1.91 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00119 / 0.00234 |
| Impact bending (drop height to failure), 12% | 21 in. |
| Heartwood decay resistance | slightly or nonresistant |
The species in this group
Lumber is often sold under a group name. These are the species the Wood Handbook reports for this group, with the same properties side by side.
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Crushing (psi) | Shrink T/R (%) | Decay resistance |
|---|---|---|---|---|---|---|---|
| Quaking aspen Populus tremuloides | 350 | 26.6 | 8,400 | 1.18 | 4,250 | 6.7 / 3.5 | slightly or nonresistant |
| Bigtooth aspen Populus grandidentata | — | 27.3 | 9,100 | 1.43 | 5,300 | 7.9 / 3.3 | slightly or nonresistant |
What it is
Aspen is the name generally applied to two species, quaking aspen (Populus tremuloides) and bigtooth aspen (P. grandidentata). Aspen lumber is produced principally in the northeastern and Lake States, with some production in the Rocky Mountain States.
The heartwood is grayish white to light grayish brown. The sapwood is lighter and usually merges gradually into the heartwood without a clear boundary. Both aspens belong to the same genus, Populus, as the cottonwoods and balsam poplar.
Working properties
Aspen is usually straight grained with a fine, uniform texture, and it is easily worked. It is lightweight and soft, low in strength, moderately stiff and moderately low in shock resistance, and the Handbook rates its shrinkage as moderately high (quaking aspen: 6.7% tangentially from green to ovendry). Well-dried aspen lumber does not impart odor or flavor to foodstuffs. Table 14-1 of the Handbook puts aspen heartwood in the slightly or nonresistant decay class.
Weight and density
At 12% moisture content quaking aspen weighs about 26.6 lb per cubic foot, so one board foot (144 cubic inches) weighs about 2.21 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 6.1 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 7.8 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
Wood movement
The Wood Handbook gives dimensional change coefficients for each species: the fraction of its width a board gains or loses for every 1% change in moisture content, between about 6% and 14%. For quaking aspen they are 0.00234 across a flatsawn face (tangential) and 0.00119 across a quartersawn face (radial).
Worked example: a flatsawn board 7-1/4 in. wide (a nominal 1×8) that goes from 6% moisture content in a heated winter house to 12% in a humid summer changes width by 7.25 × 0.00234 × 6 = 0.102 in. (about 3/32 in.). The same board quartersawn moves 0.052 in. (about 1/16 in.). Allow for this in panels, tabletops and floors; the wood movement calculator works it out for any size and moisture range.
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Quaking aspen | 350 | 26.6 | 8,400 | 1.18 | 6.7 | slightly or nonresistant |
| Eastern cottonwood | 430 | 28.0 | 8,500 | 1.37 | 9.2 | slightly or nonresistant |
| American basswood | 410 | 25.9 | 8,700 | 1.46 | 9.3 | slightly or nonresistant |
| Yellow-poplar | 540 | 29.4 | 10,100 | 1.58 | 8.2 | slightly or nonresistant |
| Eastern white pine | 380 | 24.5 | 8,600 | 1.24 | 6.1 | moderately resistant (old growth only); otherwise slightly or nonresistant |
| Red alder | 590 | 28.7 | 9,800 | 1.38 | 7.3 | slightly or nonresistant |
Uses
Lumber, pallets, boxes and crating, pulpwood, particleboard, strand panels, excelsior, matches, veneer and turned articles. Aspen is also one of the preferred species for oriented strandboard (OSB), the panel product that dominates the sheathing market.
Frequently asked questions
How hard is aspen?
Quaking aspen averages 350 lbf (1,557 N) on the Janka test at 12% moisture content and 300 lbf green, among the softest domestic hardwoods. The Wood Handbook gives no hardness value for bigtooth aspen.
Is aspen the same as poplar?
Aspen is a poplar in the botanical sense: it belongs to the genus Populus with the cottonwoods and balsam poplar. Yellow-poplar, which is also sold simply as poplar, is a different tree (Liriodendron tulipifera) and is harder than aspen (see the comparison table).
Does aspen give food a taste or smell?
No. The Wood Handbook notes that well-dried aspen lumber does not impart odor or flavor to foodstuffs.
How much does aspen weigh?
Quaking aspen weighs about 26.6 lb per cubic foot at 12% moisture content, or 2.21 lb per board foot.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 24 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.