Within garden beds and along garden paths, wood chips make an eco-friendly mulch and ground cover that complements any landscape design. Wood chips are simply formed from processing pieces of wood through a wood-chipping machine. Sometimes wood chips are formed on-location when trees or branches are cut down, and this ready-made product is then transported to other locations where it is used as a garden accent or processed in wood products.
Wood chips can come from several sources. When branches are pruned from trees on domestic and commercial properties, they can be fed into a wood chipper to make wood chips, on location. Wood chips can be produced from structurally defective trees in native forests that have to be removed but cannot be processed as sawlogs. Even the wood byproducts of sawlogs in sawmills are not discarded and are made into wood chips as well. Wood for wood chips may even come from plantation-grown young trees that are removed to give larger trees more room to grow.
Wood chips can help the soil around the base of trees retain moisture. A thick layer of wood chips, no more than 4 inches thick and extending out at least 2 feet from the tree's base, will keep the tree's root system well moistened and may lessen the watering frequency of the trees, especially in hot weather. Be careful to not pile the wood chips up to the tree trunk, as this may promote bark decay.
A way to help the soil retain moisture around plants, flowers and vegetables in the garden is to put a thick layer of wood chips over the garden's soil. Mulching the garden with wood chips up to 2 to 3 inches thick will also help to prevent weeds from growing and crowding out prized garden specimens.
Wood chips from diseased wood can spread the disease to healthy plants. This is a concern with wood chip production, since damaged or discarded wood is frequently selected to make wood chips. There is not much known about the spread of disease from wood chips to new trees, according to the University of Wisconsin. Concerns arise when considering such diseases as oak wilt and Dutch elm disease that are known to spread from tree to tree or across landscapes.
Beyond the Garden
Wood chips are used in the manufacturing process of wood products, such as paper and wood panels for building projects. They are produced as the first step of breaking the wood down into wood pulp. From the pulp stage, the material is processed into numerous wood-based products.