How Much Mulch Do I Need?
Mulch depth depends on the purpose. Flower beds need 2 inches for moisture retention. Standard garden beds do well with 3 inches. For heavy weed suppression, go with 4 inches.
The formula is simple: area (sq ft) × depth (inches) ÷ 12 = cubic feet of mulch. One cubic yard covers about 108 square feet at 3 inches deep.
Mulch Depth Guide
| Depth | Best For | Coverage per Yard |
|---|---|---|
| 2 inches | Flower beds, annual plantings | 162 sq ft |
| 3 inches | Standard garden beds, shrubs | 108 sq ft |
| 4 inches | Weed suppression, pathways | 81 sq ft |
Bulk vs Bagged Mulch
Bulk mulch costs $20–45 per cubic yard delivered. Bagged mulch (typically 2 cubic feet per bag) runs $3–6 per bag, or $40–80 per cubic yard. For anything over 3 cubic yards, bulk delivery saves 40–60%.
FAQ
How often should I replace mulch?
Top off annually in spring. Full replacement every 2–3 years, or when the mulch has decomposed into soil. Don't pile new mulch on top of thick old mulch — remove or rake the old layer first.
Can you put too much mulch?
Yes. More than 4 inches can suffocate plant roots and trap excessive moisture, leading to rot. Keep mulch 2–3 inches away from plant stems and tree trunks.