Bark dust is a type of mulch that consists of shredded or chipped tree bark. The most common trees used for bark dust are cedar, the Western hemlock and the Douglas fir. The Mulch and Soil Council guidelines stipulate that a material with ‘bark’ in the trade name needs to contain less than 15 percent wood content. Products with more than this volume of wood are defined as wood mulch rather than bark dust. The bark from a fir usually shreds into slivers and is reddish brown in color. It is not recommended to handle shredded fir bark with bare skin. Hemlock and cedar produce fewer slivers and is typically tan in color.
Bark Dust Uses
Bark dust manufactured from cedar trees is not likely to splinter; which makes it a desirable surface for children’s playgrounds. For this use a 12” deep layer is standard. Lining walkways and dog runs with cedar or hemlock bark dust is becoming increasingly popular. It is also widely used in landscaping and gardening as a tree or shrub surround due to the benefits it provides to the plant life. Not only is it aesthetically pleasing, but it also can help regulate soil temperature, hold in moisture and prevent erosion. Coarser versions can be applied as weed control. Bark dust can affect soil PH by increasing the acidity level. The soil conditions that bark mulch creates cannot be tolerated by many plants considered to be weeds. This is one of the reasons it is in such high demand. For landscaping purposes a 2” to 3” deep layer is recommended for best results.
The Bark Dust Industry
It is easy to find bark dust in Graham WA because many of the trees are native throughout the region. Bark dust can be a by-product of lumber production, recycling of yard debris or product in its own right. It is usually categorized by the plant source and coarseness of the product. It is typically sold in 200 cubic feet units, with larger loads deliverable by the truck load. Smaller quantities of bark dust can be found at local hardware and garden retailers which sell them in bags that cover 2 to 3 cubic feet. Due to the high demand for bark dust, installation and supply have become booming businesses throughout Washington and other states. A blower is normally used by installation crews, as this is much faster than hand spreading and produces an even layer.
