A couple came in certain they wanted walnut for a dining table, and left having chosen ash, which nobody expected including me. What changed their mind was a scrap of each species on the bench with a glass of water spilled on it and left for twenty minutes, plus a hard look at where the table was going: a south-facing room with three hours of direct afternoon sun. Species choice gets talked about as taste. Most of it is actually a set of measurable properties meeting a set of conditions in a particular room, and the taste part only decides between the two or three candidates that survive that filter.
Hardness is the number people ask about first
The Janka test presses a steel ball into the wood and records the force needed, which gives a rough ranking for dent resistance. White oak sits around 1,350 lbf, ash around 1,320, black walnut around 1,010. That ordering surprises people who assume walnut, being the expensive one, must be the tough one. It is not: walnut is a moderately soft hardwood that marks under a dropped pan more readily than either of the others. For a dining table with young children, that single number often decides the job. For a desk or a cabinet front that will never take an impact, it is close to irrelevant, and the conversation moves to colour and figure instead.
Movement, stability and where the board came from
Every species swells and shrinks with humidity, but not equally, and the cut matters more than the species. Quartersawn white oak moves roughly half as much across its width as the same board flatsawn, which is why it has been the traditional choice for panelled work and for anything that has to hold a tight reveal. Ash is stable and bends well, which is why it turns up in chair parts and curved rails. Walnut is reasonably stable but is usually available flatsawn, and it is frequently sold with sapwood included, which is pale and will always read as a different wood no matter what stain goes over it. The published data behind all of these figures comes from decades of testing by laboratories such as the USDA Forest Products Laboratory, whose wood handbook remains the reference most shops actually check.
Colour, and the fact that it does not stay put
This is the property clients most often get wrong, because showroom samples are finished and settled while fresh-milled timber is not. Walnut is dark when cut and lightens over several years, sometimes considerably, particularly in direct sun. White oak is pale and ambers gently, and it reacts with iron and with tannin-based treatments in ways that can be used deliberately. Ash is the palest of the three, close to white with a pronounced grain pattern, and it yellows noticeably under a standard oil finish. Anyone choosing between them for a room with strong daylight should look at a finished sample that has been sitting in a window for a month, not a fresh offcut.
Price, availability and the honest arithmetic
At the time of writing, in most US markets, kiln-dried 4/4 stock in the rough runs roughly $6 to $9 a board foot for ash, $8 to $13 for white oak with quartersawn commanding a premium, and $12 to $20 for walnut, with wide clear boards well above that. But species cost is rarely the dominant line in a commission: on a table where the material is $700 and the bench time is $4,000, choosing the cheaper species to save $250 is a poor trade if it is the wrong wood. Where species cost does bite is a whole-room package with hundreds of board feet in it, and there the sensible move is often to use the expensive species where it shows and a compatible secondary species inside the carcase, which is exactly what cabinetmakers have done for three centuries.
Frequently asked questions
Can ash be stained to look like walnut? It can be darkened convincingly in photographs and far less convincingly in a room. The pore structure and figure are different, and the stain sits in the grain unevenly, which reads as an imitation up close.
Is white oak really more water-resistant than red oak? Yes, measurably. White oak’s pores are blocked by tyloses, which is why it has historically been used for barrels and boat building, while red oak’s open pores will draw water along the grain.
Does ash have a future given emerald ash borer damage? Supply has been volatile and regionally uneven since the beetle spread, with salvage cutting sometimes making good material unusually available. It is worth asking a supplier about current stock rather than assuming either scarcity or abundance. Salvaged stock deserves its own scrutiny, and what to refuse when buying reclaimed timber applies directly here.