20 × 30 ft bed: the short answer
At 3 inches deep, a 20 × 30 ft bed needs about 150.0 cubic feet of mulch — roughly 75 bags of 2 cu ft, or about 5.56 cubic yards in bulk.
Bed size
Mulch for a 20 × 30 ft bed
A 20 × 30 ft bed at 3 inches deep needs about 150.0 cubic feet of mulch — about 75 bags of 2 cu ft, or 5.56 cubic yards in bulk. Adjust depth and bag size below.
Mulch needed
—Enter bed size and depth to estimate mulch.
| Total volume | — |
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| Bulk (cubic yards) | — |
| Bags to buy | — |
| Coverage per bag | — |
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Shopping list
Run the calculator to prepare a list.
Estimate only.
Mulch is typically applied 2–3 inches deep (3–4 inches for weed suppression). Bag counts are
rounded up; coverage varies with how finely the mulch is shredded and how much it settles.
Before you buy
Mulch settles and breaks down, so topping up to 3 inches each year is normal rather than piling it deeper. For more than 8–10 bags, compare bulk delivery by the cubic yard.
Standard volume math at 3″ depth; 1 cu yd = 27 cu ft. Estimates only.
What a 20 × 30 ft bed usually needs
A 20 × 30 ft area is a large-scale mulching project: 600 sq ft of coverage that, at 3 inches, needs about 1.7 cubic yards of material. This is full delivery territory, often split across two or more loads depending on the supplier's truck capacity and how much the bed can take at once.
How to decide
Plan the job in stages: measure the exact bed, choose a consistent depth within the 2–4 inch range, then convert to the supplier's selling unit. For a job this large, get the quote per cubic yard and confirm how it will be delivered and where it can be dumped. Splitting delivery can reduce double-handling but may add a delivery fee, so compare both options.
Checks before you order
- Measure the bed in sections and add the areas rather than guessing an average size.
- Compare single versus split delivery pricing and access for the truck.
- Confirm the depth target with the plants in the bed before ordering the volume.
FAQ
How much mulch for a 20 × 30 ft bed?
At 3 inches deep, a 20 × 30 ft bed needs about 150.0 cubic feet (5.56 cubic yards) of mulch — roughly 75 bags of 2 cu ft. Deeper mulch scales directly: 4 inches needs about a third more than 3 inches.
How many bags of mulch for a 20 × 30 ft bed?
About 75 bags of 2 cu ft at 3 inches deep. If that's more than 8–10 bags, price out bulk mulch by the cubic yard (5.56 cu yd here) — it's usually cheaper.
Sources & verification
Source links and page assumptions reviewed .
- University of Minnesota Extension: mulching for soil and garden health — Recommends 2–4 inches of mulch and keeping it clear of plant stems and trunks.
Estimate only, based on standard volume math at 3″ depth. Coverage varies with mulch type and settling; bag counts are rounded up. Confirm against your supplier before buying.