Alder wood often raises questions about its classification, especially regarding its perceived softness. While “soft wood” might suggest a lack of durability, the distinction between hardwood and softwood is botanical, not solely based on physical hardness. This article clarifies alder’s true classification and its practical properties, explaining its popularity for various applications.
Alder’s Classification: A Hardwood by Definition
Despite its relatively yielding nature, alder is botanically classified as a hardwood. This is because alder trees are deciduous, shedding their leaves annually. Its wood is widely used in commercial applications. The misconception about alder being a softwood often arises because its physical hardness, measured on the Janka scale at around 590 lbf, is lower than many other hardwoods like oak or maple. However, this indicates a softer end of the hardwood spectrum, not a reclassification to softwood.
Understanding Hardwood and Softwood Categories
The fundamental difference between hardwoods and softwoods lies in their botanical origins. Hardwoods come from angiosperm trees, which are flowering plants with broad leaves and enclosed seeds. Their wood features vessels or pores that transport water and nutrients.
In contrast, softwoods come from gymnosperm trees, which are cone-bearing and have needle-like leaves that remain green year-round, with exposed seeds. Softwoods have a simpler cellular structure, lacking the distinct vessels found in hardwoods. Importantly, the terms “hardwood” and “softwood” do not always correlate with physical hardness; some hardwoods are softer than some softwoods, and vice versa.
Practical Properties of Alder Wood
Alder wood has properties that make it desirable for various uses. It presents a light tan to reddish-brown color, which can deepen with age, and has a straight grain with a fine, uniform texture. This consistent appearance makes it an attractive material for furniture and cabinetry. Alder is easy to work with using both hand and machine tools, sanding and turning well due to its moderately soft nature. Its medium density contributes to its ease of handling and manipulation.
The wood responds well to stains and finishes, allowing it to mimic more expensive woods like cherry or walnut, making it a cost-effective alternative. While it has moderate bending strength and shock resistance compared to denser hardwoods, alder offers good dimensional stability once dried, minimizing movement in finished products. Its workability and ability to take stains uniformly position alder as a versatile material for interior applications such as drawer sides, panels, and various turned objects.