Bark Mulch

Bark mulch starts as bark stripped during lumber milling, then either shredded into long stringy pieces or run through a tub grinder and screened into nugget grades, typically under 1 in, 1 to 2 in, and 2 to 3 in and larger. Shredded bark interlocks into a mat that resists wind and light rain but compacts and sheds water over a season or two. Nugget bark stays looser and drains better between pieces but is lighter per piece and more prone to floating away in a downpour. Species varies by region rather than by grade. Fir and hemlock bark dominate West Coast supply because that is what regional mills process, giving a reddish brown color and a slightly resinous smell. East of the Rockies, pine bark and hardwood bark are more common, with pine running lighter and hardwood darker. None of these species differences change how the mulch performs much, they mostly affect color and regional availability, plus what your supplier calls it, bark mulch versus bark dust.

Clear existing weeds and debris first, then edge the bed so the mulch has a defined boundary instead of spreading into turf. Skip landscape fabric under bark mulch in most cases, since it blocks the mulch from feeding the soil as it breaks down and tends to surface again as the layers shift. Adequate depth alone, 2 to 3 in in most beds, does the weed suppression work fabric is meant to do. Spread bark mulch evenly with a rake, keeping it a few inches back from trunks, stems, and foundations to avoid trapping moisture against wood or siding. Water lightly after installing shredded bark so it starts to knit together and resists blowing off before it settles. Check depth again in six months, since shredded bark mats and compresses faster than nuggets and may need a thin top off sooner than the yearly norm to keep coverage even.

Compared with wood chips. Arborist wood chips mix shredded branches, leaves, and bark together, often at low cost from tree services, and break down faster while actually feeding the soil. Bark mulch alone is more uniform and decorative and lasts longer, but returns fewer nutrients to the soil as it slowly decomposes.

Compared with rock or gravel mulch. Stone mulch never breaks down and never needs annual replacement, but it adds no organic matter, heats up more in summer sun, and is far harder to remove or rearrange later. Bark mulch feeds soil over time and stays easier to adjust as beds change.

How much bark mulch do I need. Multiply your bed's square footage by the depth in inches, then divide by 324 to get cubic yards, since 1 cubic yard covers 324 sq ft at 1 in deep. At the standard 3 in depth, figure roughly 1 cubic yard per 108 sq ft. Measure irregular beds in sections and round up slightly, since fresh mulch settles as it sits.

How bark mulch is sold and delivered. Bulk bark mulch is sold by the cubic yard rather than by the bag, which is more economical for anything beyond a small border. It arrives loose, dumped in a driveway or designated spot for you to spread with a wheelbarrow and rake, or a fork if the load is large. Ask about moisture content if timing a delivery around rain, since wet mulch weighs and handles differently than dry.