Red alder and yellow-poplar are close to twins on paper: two light, soft, easy-working hardwoods sold at modest prices. The difference is mostly where they grow and how they look under a finish. Red alder is the principal commercial hardwood of Oregon and Washington; yellow-poplar comes from the eastern United States, with most production in the South and Southeast. This page compares them with Wood Handbook data.
Alder vs Poplar: the numbers
| Property | Red alder | Yellow-poplar |
|---|---|---|
| Janka side hardness, 12% MC | 590 lbf | 540 lbf |
| Density at 12% MC | 28.7 lb/ft³ | 29.4 lb/ft³ |
| Weight per board foot | 2.39 lb | 2.45 lb |
| Bending strength (MOR), 12% MC | 9,800 psi | 10,100 psi |
| Stiffness (MOE), 12% MC | 1.38 million psi | 1.58 million psi |
| Crushing strength parallel to grain | 5,820 psi | 5,540 psi |
| Shrinkage green to ovendry, tangential | 7.3% | 8.2% |
| Shrinkage, radial | 4.4% | 4.6% |
| Shrinkage, volumetric | 12.6% | 12.7% |
| Tangential / radial ratio (cupping tendency) | 1.66 | 1.78 |
| Width change per 1% MC, flatsawn (Table 13-5) | 0.256% | 0.289% |
| Heartwood decay resistance (Table 14-1) | slightly or nonresistant | slightly or nonresistant |
What the numbers mean
- Hardness: Red alder is 9% harder than Yellow-poplar (590 against 540 lbf), so it resists dents from furniture feet, dropped tools and wear correspondingly better.
- Weight: Yellow-poplar is 2% heavier. A 1 x 6 board 8 feet long (4 board feet nominal) weighs about 9.8 lb in yellow-poplar and 9.6 lb in red alder at 12% moisture content.
- Strength and stiffness: Yellow-poplar is 3% stronger in bending and 14% stiffer. Stiffness is what decides how much a shelf of the same size sags under the same load.
- Movement: a flatsawn board 10 in wide that goes from 6% to 12% moisture content (a dry winter to a humid summer indoors) swells about 0.154 in (5/32 in) in red alder and 0.173 in (3/16 in) in yellow-poplar, from Handbook Eq. 13-2 and the Table 13-5 coefficients. Allow for this in table tops, panels and floors.
- Decay resistance of the heartwood: Red alder: slightly or nonresistant; Yellow-poplar: slightly or nonresistant. Sapwood of every species has low decay resistance.
Appearance, working and what to watch for
Red alder is almost white to pale pinkish brown when cut, with no visible boundary between heartwood and sapwood, and it turns a warm honey brown with age. Its even colour and fine texture make it one of the best woods for taking stain evenly, so it is often stained to imitate cherry or walnut. Knotty alder, with small sound knots, is a popular rustic cabinet grade. Yellow-poplar has creamy sapwood and yellowish brown heartwood with green, purple or dark streaks, so it is mainly a paint-grade wood.
Mechanically there is little between them. Alder is a touch harder, poplar a touch stronger and stiffer in bending, and both are low in shock resistance. The Handbook notes that red alder has relatively low shrinkage; in our data it moves a little less than yellow-poplar across a flatsawn board. Both machine, glue and nail easily, and both are slightly or nonresistant to decay, so neither belongs outdoors.
Staining tips
Even alder benefits from a conditioner or washcoat before a dark stain, because its softer earlywood absorbs more stain. Test on an offcut from the same boards. For yellow-poplar, if you want a stained look, use a gel stain or a toner over a sealer coat rather than a penetrating stain, and sort boards to avoid the darkest green and purple heartwood on show faces.
Which to choose: verdict by use
| Use | Better choice | Why |
|---|---|---|
| Stained cabinets with a uniform colour | Alder | Even colour and texture take stain well. |
| Rustic or knotty cabinets | Alder | Knotty alder is a standard cabinet grade. |
| Painted trim, doors and cabinets | Poplar | Cheaper in the East; streaks vanish under paint. |
| Furniture in the Pacific Northwest | Alder | The local hardwood and the Handbook's principal use for it. |
| Secondary wood and drawer parts | Either | Similar strength, weight and stability. |
| Floors | Neither | Both are soft; choose oak, maple or hickory. |
Frequently asked questions
Is alder harder than poplar?
Slightly. Red alder has 590 lbf of Janka hardness and yellow-poplar 540 lbf in the Wood Handbook. Both dent easily compared with oak or maple.
Does alder stain better than poplar?
Usually yes. Alder has a uniform pale colour with no streaks, so it takes stain evenly; yellow-poplar’s green and purple streaks often show through stain.
Which is cheaper, alder or poplar?
It depends on where you are. Yellow-poplar is usually the cheaper hardwood in the eastern US, and red alder in the West, near where each is cut.
Sources and method
All property values are read from our parsed copy of the USDA Forest Products Laboratory Wood Handbook: Wood as an Engineering Material (FPL-GTR-190, 2010), a US Government publication in the public domain, the same data as the wood species database. The percentages and the board examples above are our arithmetic on those values. The values describe small, clear, straight-grained specimens: real boards with knots or sloping grain differ, and structural lumber is sized from graded design values in your local building code, not from this table.
- 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. How we build and check our data: methodology and corrections. Spotted an error? Please let us know.