How Much Mulch Do You Need? Depth and Coverage Table
How deep to mulch, how far a bag or a cubic yard goes, and a coverage table for common bed sizes.
Mulch is easy to under-buy: a pile that looks huge in the driveway disappears fast once it’s spread. Work it out from the area and the depth.
How deep should mulch be?
- 2–3 inches for most garden beds. Enough to keep moisture in and weeds down.
- 3–4 inches where weeds are a big problem or the mulch is coarse, like large bark nuggets.
- No more than about 4 inches around plants. Thicker layers can keep water and air from reaching roots.
Keep mulch a few inches back from tree trunks and plant stems. Piling it up against bark (the “mulch volcano”) traps moisture and invites rot and pests.
If you’re topping up existing mulch, only add enough to bring the total back to 2–3 inches.
Coverage table
Bags are the standard 2 cubic foot size.
| Area | At 2”: cu yd | At 2”: bags | At 3”: cu yd | At 3”: bags |
|---|---|---|---|---|
| 50 sq ft | 0.31 | 5 | 0.46 | 7 |
| 100 sq ft | 0.62 | 9 | 0.93 | 13 |
| 200 sq ft | 1.23 | 17 | 1.85 | 25 |
| 300 sq ft | 1.85 | 25 | 2.78 | 38 |
| 500 sq ft | 3.09 | 42 | 4.63 | 63 |
| 1000 sq ft | 6.17 | 84 | 9.26 | 125 |
Quick coverage figures
- One 2 cu ft bag covers about 12 sq ft at 2”, or 8 sq ft at 3”.
- One cubic yard covers about 162 sq ft at 2”, or 108 sq ft at 3”.
- One cubic yard equals about 13.5 bags of 2 cu ft.
How to measure your beds
For a rectangle, multiply length by width in feet. For a circle around a tree, multiply the radius by itself and by 3.14. For odd shapes, break the bed into rectangles and circles, work out each one and add them up, or pace it out and round up.
Bags or bulk?
Bags are tidy, easy to carry and good for a few small beds. Above about 2 cubic yards (27 bags), bulk delivery is usually much cheaper per yard, even with a delivery fee. Bulk mulch is often fresher, too. Have it dumped on a tarp close to where you’ll use it.
Types of mulch
- Shredded hardwood: knits together, stays put on slopes, breaks down into the soil over a year or two.
- Pine bark nuggets: long-lasting and attractive, but can float and wash away in heavy rain.
- Pine straw: light and quick to spread, popular in the US Southeast. One bale covers very roughly 40–50 sq ft.
- Dyed mulch: holds color longer; check that the dye is a plain colorant.
- Wood chips from tree services: often free; best for paths and around trees.
Enter your beds in the mulch section of the planner to compare bags and bulk with your own prices.