How Much Mulch Do I Need?

2–3 inches of mulch is standard for most garden beds — enough to suppress weeds and retain moisture without smothering plant crowns. New beds or areas with heavy weed pressure often use 3–4 inches instead.

Mulch volume follows the same formula as any bulk material (area × depth ÷ 27 for cubic yards), but it's also commonly sold bagged — almost always in 2 cubic foot bags — which matters for small beds where bulk delivery isn't practical.

The Mulch Calculator gives you both cubic yards for bulk orders and a bag count for bagged purchases.

Organic mulch (bark, wood chips) breaks down over time and typically needs topping off annually at about half the original depth. Inorganic mulch (rubber, rock) doesn't decompose, but it also doesn't improve soil health the way organic mulch does as it breaks down.