How deep to go
| Use | Published figure | Source |
|---|---|---|
| Mulch depth (University of Kentucky) | 2 to 3 in, 3 in maximum | publications.ca.uky.edu |
| Organic mulch (Utah State) | 3 to 4 in | extension.usu.edu |
| Ring width around a lawn tree (Mississippi State) | 3 to 6 ft | extension.msstate.edu |
University of Kentucky Extension says mulch should be no deeper than 2 or 3 inches and should reach the tree's dripline, never piled against the trunk. Utah State suggests 3 to 4 inches of organic mulch and notes that a 2-inch layer takes about 6 cubic yards per 1,000 sq ft. The calculator subtracts nothing for the trunk, which is small next to the ring.
Working it out
Cubic yards = area (sq ft) × depth (in) ÷ 12 ÷ 27. Tons = cubic yards × weight per cubic yard.
Example: 6 ft circle × 4 at 3 inches is 1.05 cubic yards of mulch, about 0.26 tons at 0.25 tons per cubic yard.
Rochester Concrete Products' install guide adds 10% for compaction and uneven ground.
Common questions
How much gravel do I need for a mulch around trees?
Measure the area, choose a depth from the table above and enter both in the calculator. It gives cubic yards, tons and bags.
Should I order extra?
Rochester Concrete Products' install guide adds 10% for compaction and uneven ground. Loose stone also compacts, so a compacted layer needs more loose material than its finished depth suggests.
Related calculators
Sources
- https://publications.ca.uky.edu/sites/publications.ca.uky.edu/files/ho106.pdf
- https://extension.usu.edu/cwel/research/water-wise-landscaping-mulch.php
- https://extension.msstate.edu/publications/mulches-for-the-landscape
- https://www.thecalculatorsite.com/articles/units/how-much-cubic-yard-weigh.php