Mulch is sold by the cubic yard, but you measure your beds in square feet, so the question is always how to connect the two. Here is the short answer: one cubic yard of bark mulch covers about 100 square feet at 3 inches deep. Go shallower and it stretches further, go deeper and you need more. This guide gives you the formula, a coverage table, and how deep to spread it, so you can order bark mulch by the yard without guessing.
The quick formula
- Measure the length and width of your bed in feet and multiply for square feet.
- Pick a depth in inches and divide by 12 to get feet.
- Multiply square feet by that depth to get cubic feet.
- Divide cubic feet by 27 to get cubic yards.
Example: a 400 square foot bed at 3 inches deep is 400 multiplied by 0.25, which is 100 cubic feet, or about 3.7 cubic yards. Round up a little so you are not short.
Coverage at a glance
One cubic yard equals 27 cubic feet. Here is what a yard of mulch covers at common depths:
| Depth | Coverage per cubic yard |
|---|---|
| 1 inch | ~324 sq ft |
| 2 inches | ~162 sq ft |
| 3 inches | ~108 sq ft |
| 4 inches | ~81 sq ft |
Most beds do best with 2 to 3 inches of mulch, so a cubic yard covering roughly 100 to 160 square feet is a good planning number.
How deep should bark mulch be?
- Maintaining an existing bed: 1 to 2 inches to refresh the look and keep coverage.
- New beds and weed suppression: 3 inches, which blocks most light to weed seeds.
- Around trees and shrubs: 2 to 3 inches, kept a few inches back from trunks and stems.
Avoid piling mulch against trunks. A volcano of mulch traps moisture against the bark and invites rot. Keep a small gap around the base.
Why mulch is worth it
A few inches of bark mulch does real work in a bed. It holds soil moisture so you water less, blocks light to keep weeds down, moderates soil temperature through hot and cold spells, and breaks down over time to feed the soil. It also gives beds a clean, finished edge that ties a landscape together. Our guide to landscaping with bark mulch covers design and placement once you have the quantity settled.
Shop bark mulch and colored chips
Brown Colored Landscape Mulch
Black Mulch Medium
Brown Colored Chips
Black Colored Wood Chips
Brown Colored Mini Chips
Black Colored Mini Chips
Mini chips give a finer texture that stays put on slopes; the larger chips read coarser and last a little longer before they need topping off. Also stocked: Gorilla Hair Redwood Bark, which knits together and resists blowing away, and Red Colored Landscape Mulch.
Why mulch is ordered by volume, not weight
Rock is sold by the ton because it is heavy. Mulch is not. A cubic yard of bark mulch weighs roughly 700 pounds, against about 2,700 pounds for decomposed granite and 2,800 for landscape rock. That is why nobody quotes mulch in tons: the tonnage would be a fraction of a ton for a bed that takes several yards, and the number would tell you nothing useful about coverage.
It also changes how a load arrives. A truck hits its volume limit on mulch long before it hits its weight limit, which is the opposite of a rock load. Our guide on cubic yards vs tons explains which unit each material uses, and how bulk material is delivered covers what to expect on the day. For larger jobs, the bulk delivery guide covers load sizes and access.
How often to replace it
Bark mulch breaks down gradually, so plan to top it off about once a year to keep your depth and color. You usually do not need to remove the old layer. Just rake it to loosen any matting and add fresh mulch on top to your target depth. Because you are refreshing rather than rebuilding, a top-off usually needs 1 to 2 inches, which is roughly half the material of a new bed.
What goes under and around the mulch
Mulch performs better with the right layers beneath and a hard edge around it.
- Soil first. If the bed is new or tired, amend it before mulching. Browse garden soils and amendments.
- Fabric where weeds are bad. Weed fabric under mulch cuts regrowth, though mulch alone at 3 inches does most of the work.
- Edging to hold the line. Mulch migrates onto lawns and paths without a border. See edging and our landscape edging guide.
Edging that holds a mulch bed
Mulch or rock for your beds?
Mulch feeds the soil and looks warm, but it breaks down and needs replacing every year. Rock and decomposed granite cost more up front and last for years with almost no upkeep, which matters in hot, dry climates where mulch bleaches and blows around. Many yards use both: mulch in planted beds, rock in the open ground cover areas.
If you are weighing the two, decomposed granite vs mulch compares them head to head, and rock around plants and garden beds covers using stone where you would normally mulch. On the product side, compare decomposed granite, landscape rock, and pea gravel.
Wanting the mulch look without the yearly top-off? Mineral Mulch is a stone product sized like bark mulch that does not break down.
Sizing the rest of the project
If your yard needs more than mulch, these guides run the same math for each material:
- How much landscape rock do I need
- How much decomposed granite do I need
- How much river rock do I need
Frequently asked questions
How much does a yard of mulch cover?
About 100 square feet at 3 inches deep, or roughly 160 square feet at 2 inches. One cubic yard is 27 cubic feet, so coverage scales with how deep you spread it.
How many bags of mulch are in a cubic yard?
Bagged mulch is often sold in 2 cubic foot bags, so a cubic yard is about 13 to 14 bags. For larger beds, buying bulk by the yard is usually more economical.
How deep should I spread bark mulch?
Two to three inches is ideal for most beds. Three inches helps suppress weeds in new beds, while 1 to 2 inches refreshes an existing layer. Keep mulch a few inches off trunks and stems.
How often should I add new mulch?
About once a year. Bark mulch breaks down over time, so topping it off annually maintains your depth, color, and weed suppression. Rake the old layer first, then add fresh on top.
How much does a cubic yard of bark mulch weigh?
Roughly 700 pounds, though it goes heavier when wet. That is about a quarter the weight of a cubic yard of landscape rock, which runs near 2,800 pounds, and it is why mulch is sold by volume rather than by the ton.
How much mulch do I need for a 1,000 square foot bed?
At 3 inches deep, about 9 to 10 cubic yards. At 2 inches, about 6 cubic yards. Round up rather than down, since coming up half a yard short means either a thin patch or a second delivery.
Should I use mulch or rock in my beds?
Mulch feeds the soil and suits planted beds, but it breaks down and needs topping off yearly. Rock and decomposed granite last for years with little upkeep and hold up better in hot, dry climates. Many yards use mulch in planted beds and rock in open ground cover areas.
Order your mulch
Figure your beds with the coverage calculator, then browse our bark mulch and topsoil. Popular picks are Brown Colored Landscape Mulch for a classic bed and Black Mulch Medium for high contrast against green planting. We deliver nationwide from our California yards, by the bag or by the truckload. For large loads or long-distance delivery, request a quote and we will work out freight.