Every year homeowners and landscapers use mountains of shredded bark mulch in shrub and and flower beds, around trees, on hiking trails and in plant nurseries.
In addition to improving the aesthetics of a landscape, mulch helps prevent erosion, controls weeds, adds organic matter, makes a good walking surface in muddy areas and holds moisture in the ground around landscape plants.
Shredded bark mulch is usually sold as single, double or triple shredded, with the single shredded being the coarsest and the triple shredded the finest. Single shredded is the form of mulch that comes directly from the saw mill. Double and triple shredded mulches are created by regrinding the mulch in a tub grinder, further reducing the particle size.
Even though single shredded mulch is much less uniform with more large pieces of bark mixed into the product, it does last the longest when applied to landscape beds. The finer ground mulches are more popular due to their more uniform particle size, but they do tend to break down more rapidly.
Shredded bark mulch is a by-product of the timber industry. Before rough cut logs can be moved into a saw mill to be cut into lumber, they must first have the tree bark removed. This debarking process not only removes the unwanted bark, it also removes dirt and debris which may otherwise damage circular saw blades in the milling process.