How Much Mulch for a 10x20 Garden Bed? (2026 Guide)
A 10×20 ft (200 sq ft) bed at 2 in deep needs about 33 cu ft of mulch: buy 2 cubic yards of bulk or 17 bags of 2-cu-ft; at 3 in deep, about 2 cubic yards (25 bags).
How much mulch a 10×20 ft bed takes
A 10×20 ft bed works out to 200 sq ft — about the footprint of two compact parking stalls. Convert to cubic feet with area × depth in inches ÷ 12, then divide by 27 to get cubic yards. Bag counts below are rounded up, because mulch bags are only sold whole:
| Depth | Mulch volume (cu ft) | Cubic yards | 2-cu-ft bags | 3-cu-ft bags |
|---|---|---|---|---|
| 1 in | 16.7 | 0.62 | 9 | 6 |
| 2 in | 33.3 | 1.23 | 17 | 12 |
| 3 in | 50 | 1.85 | 25 | 17 |
| 4 in | 66.7 | 2.47 | 34 | 23 |
Bulk mulch is delivered and billed by the full cubic yard, so round your order up: 2 in → 33.3 cu ft (1.23 yd³) calls for a 1.5–2 yd order; 3 in → 50 cu ft (1.85 yd³) rounds to 2 yd; 4 in → 66.7 cu ft (2.47 yd³) rounds to 3 yd. As for depth itself: flower beds usually run 2–3 in — enough to hold moisture and hold down weeds — and you should never mound mulch against tree trunks or shrub bases, where trapped moisture rots the bark.
Worked example: 200 sq ft at 3 in deep
Say the bed is a clean 10×20 ft and you want a full 3 in of mulch. Cubic feet first: 200 × 3 ÷ 12 = 50 cu ft. In cubic yards, 50 ÷ 27 ≈ 1.9 yd³, so a bulk delivery rounds up to 2 cubic yards. Bagged instead? 50 ÷ 2 = 25 bags of 2-cu-ft mulch, with none left over (or 17 bags of 3-cu-ft). The same bed at 2 in needs 33.3 cu ft (17 bags) and at 4 in needs 66.7 cu ft (34 bags). Try a different depth or a slightly different size with the mulch calculator before you order.
Three checks before you order
- Measure the actual bed. Mulch is sold by volume, and few beds come out an exact 10×20 — a bed that is really 10×22 ft needs about 10% more mulch. Measure the length and the average width in feet, multiply, and use that area.
- Skip paths and groundcover. Only the soil you are covering counts: subtract walkways, stepping stones, and plants that spread as living groundcover. Mulching over them wastes material and can smother the plants.
- Weigh bulk versus bags. Bulk mulch typically costs about half as much per cubic yard as the same volume in 2-cu-ft bags, but it arrives as one truckload dump — so bags suit the small 2 in job, while bulk pays off at 3–4 in if you have a spot to take delivery.
Covering a different area? See how much mulch a 10×10 garden bed needs, how much mulch a 4×8 raised bed takes, or how much topsoil you need when you are refreshing the bed itself. For any other bed size, run the mulch calculator — it gives the exact bags and yards in seconds.
FAQ
How much mulch does a 10×20 garden bed need at 3 in deep?
About 50 cu ft — call it 2 cubic yards — which is 25 bags of 2-cu-ft mulch, or 17 bags of 3-cu-ft. That covers the full 200 sq ft evenly at 3 in, the top of the usual 2–3 in range for flower beds.
Is 2 in or 3 in of mulch better?
Both work in a flower bed: 2 in holds moisture and looks tidy, while 3 in suppresses weeds better and protects roots from summer heat and winter cold — most beds land somewhere in the 2–3 in range. Deeper is not better: piling mulch thick against tree trunks or shrub bases traps moisture against the bark, so keep those spots at 2–3 in too.
How big is a 200 sq ft garden bed?
It is exactly a 10×20 ft rectangle. For scale, that is roughly two compact parking stalls side by side (each about 100 sq ft): a full-size stall runs closer to 160 sq ft, so 200 sq ft is a bit bigger than one stall and about two compact ones.
Need a different size?
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