Mulch for a 20×20 ft Garden at 3 Inches Deep
A square 20×20 ft garden area at 3 inches of mulch depth requires approximately 3.7 cubic yards.
How to use this tool
- Enter the garden bed length and width in feet.
- Choose mulch depth in inches (2–4 in is typical).
- The result shows cubic yards needed and equivalent number of 2 cu ft bags.
A 20×20 ft vegetable or flower garden at 3 inches of mulch needs about 3.7 cubic yards to effectively cover and protect the soil.
Frequently asked questions
- How much mulch do I need?
- Multiply the bed area (ft²) by depth (in inches ÷ 12) to get cubic feet. Divide by 27 for cubic yards. A standard bag holds 2 cubic feet.
- How deep should mulch be?
- Apply 2–3 inches for most garden beds. Avoid piling mulch against plant stems (volcano mulching), which can cause rot.