Wood spalting is a natural process that occurs when fungi start to grow on wood, particularly on dead or decaying wood. The fungi grow in the wood and create intricate patterns of contrasting colors and lines, which are known as spalting.
The process of wood spalting can create a range of colors and patterns in the wood, including black, gray, blue, and green lines, spots, and streaks. These patterns can be quite beautiful and unique, making spalted wood a desirable material for woodworking and artistic purposes.
Spalting can occur in different types of wood, but it is most commonly seen in hardwoods such as maple, beech, birch, and oak. The process is influenced by several factors, including the type of fungi present, the moisture content of the wood, and the temperature and humidity of the environment. But most importantly level of sugar in tree sap. Birch is very sweet wood and is attacked colonized with fungi very quickly.
While spalted wood can be visually stunning, it can also be weaker than unspalted wood due to the decay caused by the fungi. I use spalted wood that is still strong enough to be worked on.
Fungus growth stops when wood is dry.