Distinguishing Between Hardwood and Softwood Trees

The terms hardwood and softwood are widely used in the construction industry and among woodworkers to distinguish between species with wood regarded as hard and durable and those that are considered soft and easily shaped. And while this is generally true, it is not an absolute rule.

Distinctions Between Hardwood and Softwood

In reality, the technical distinction has to do with the reproductive biology of the species. Informally, trees categorized as hardwoods are usually deciduous — meaning they lose their leaves in the autumn. Softwoods are conifers, which have needles rather than traditional leaves and retain them through the winter. And while generally speaking the average hardwood is a good deal harder and more durable than the average softwood, there are examples of deciduous hardwoods that are much softer than the hardest softwoods. An example is balsa, a hardwood that is quite soft when compared to the wood from yew trees, which is quite durable and hard.

Really, though, the technical distinction between hardwoods and softwoods has to do with their methods for reproducing. Let's look at hardwoods and softwoods one at a time. 

Hardwood Trees and Their Wood

• Definition and Taxonomy: Hardwoods are woody-fleshed plant species that are angiosperms (the seeds are enclosed in ovary structures). This might be a fruit, such as an apple, or a hard shell, such as an acorn or hickory nut. These plants also are not monocots (the seeds have more than one rudimentary leaf as they sprout). The woody stems in hardwoods have vascular tubes that transport water through the wood; these appear as pores when wood is viewed under magnification in cross-section. These same pores create a wood grain pattern, which increases the wood's density and workability.
• Uses: Timber from hardwood species is most commonly used in furniture, flooring, wood moldings, and fine veneers. 
• Common species examples: Oak, maple, birch, walnut, beech, hickory, mahogany, balsa, teak, and alder.
• Density: Hardwoods are generally denser and heavier than softwoods. 
• Cost: Varies widely, but typically more expensive than softwoods.
• Growth rate: Varies, but all grow more slowly than softwoods, a major reason why they are more expensive.
• Leaf structure: Most hardwoods have broad, flat leaves that shed over a period of time in the fall.

Softwood Trees and Their Wood

• Definition and Taxonomy: Softwoods, on the other hand, are gymnosperms (conifers) with "naked" seeds not contained by a fruit or nut. Pines, firs, and spruces, which grow seeds in cones, fall into this category. In conifers, seeds are released into the wind once they mature. This spreads the plant's seed over a wide area, which gives an early advantage over many hardwood species.
• Softwoods do not have pores but instead have linear tubes called tracheids that provide nutrients for growth. These tracheids do the same thing as hardwood pores — they transport water and produce sap that protects from pest invasion and provides the essential elements for tree growth.
• Uses: Softwoods are most often used in dimension lumber for construction framing, pulpwood for paper, and sheet goods, including particleboard, plywood, and fiberboard.
• Species examples: Cedar, Douglas fir, juniper, pine, redwood, spruce, and yew.
• Density: Softwoods are typically lighter in weight and less dense than hardwoods.
• Cost: Most species are considerably less expensive than hardwoods, making them the clear favorite for any structural application where the wood will not be seen.
• Growth rate: Softwoods are fast-growing as compared to most hardwoods, one reason why they are less expensive.
• Leaf structure: With rare exceptions, softwoods are conifers with needle-like "leaves" that remain on the tree year-round, though they are gradually shed as they age. In most cases, a softwood conifer completes a changeover of all its needles every two years.