Heartwood refers to the interior of many types of trees. As the tree ages, it loses its ability to pass sap through the inner parts of the tree, causing death of these parts. The inner part, once dead, often becomes darker than the exterior wood, and frequently becomes stronger, making it more suitable for certain kinds of uses in building, craft work, and woodwork. It is contrasted to sapwood, which is the outer layer of the wood that still possesses ability to move sap and is living. Sapwood tends to have more spring and less stability.
Some people prefer heartwood in building due to the darker colors it may possess. Cherry or walnut heartwoods, for instance, are favored for their rich, deep coloration, which may require little staining. Not all heartwood is that much darker than its surrounding sapwood, however. Rather, it can be said that the interior dead wood can potentially be much more colorful than the exterior live wood. Color really depends on tree species and those favoring darker wood hues should look for lumber or wood pieces from specific trees, where extreme darkening is a characteristic of interior wood death.
Builders and woodworkers are often fans of heartwood because it can be so strong. Some craftspeople find it ideal for making things like long lasting cabinetry. Heartwood cedar is favored to make ornate and durable cedar chests, which may truly last a lifetime. Woodworkers could also use this wood material to create a variety of storage or jewelry boxes, and to make things like birdhouses. Some people enjoy making large or small carvings such as useful and attractive wooden bowls or intricate artistic representations in heartwoods of varying types.
A number of other uses for heartwood are easy to identify. It might be used to make tool handles, which will be stiff and sturdy, or as pieces in certain musical instruments like violins and cellos. The area of distinction between inner and outer wood has been one of much scholarly debate in the music world, especially on the issue of the making of Stradivarius violins. Finely tuned analysis of exactly what woods were used and whether they were heart or sapwood has been debated to determine if it’s possible to replicate Stradivarius’ genius today.
What can be said, though, is that heartwood isn’t exactly a type of tree or lumber, and it shouldn’t be confused with the term hardwood. Instead, it references a process that occurs in a tree over time, as the inner core loses its ability to transmit sap and changes in nature so that it is different from the outside of the tree, and all parts of the tree that are still sapwood. The specific characteristics and usage of any of this dead wood continue to be highly dependent on the type of tree it is. The inner dead parts of the tree may not be all that different than its sapwood surroundings, but sometimes the change results in delightfully resilient wood that is useful in many ways.