How Much Mulch Do You Need for Garden Beds?

Sketch each bed as rectangles or use length × average width for curved edges. Subtract large hardscape (patios, paths) that will not be mulched.

If beds wrap a house, measure along the foundation and out to the bed edge in a few places, then average the depth of the bed.

Most bark and wood mulches are planned at 2–3 inches (50–75 mm). Thinner layers dry out and leave bare patches; much thicker layers can stay too wet against stems.

When refreshing an existing bed, you often need less than a full new depth — scrape back compacted old mulch and top up rather than stacking another full 3 inches on top every year.

Bag coverage charts assume a stated depth. Divide your cubic volume by the bag volume to get bag count, then round up. Bulk delivery is usually cheaper above a few cubic yards but needs a place to dump.

Run the Mulch Calculator once with your area and depth, then decide bags versus bulk from the volume output — not from a guess at ‘a few bags’.

Edging, landscape fabric, and plant spacing are separate. Fabric under mulch changes how much you need only if you are building a new bed from bare soil.

Coloured or rubber mulches have different coverage; always check the product label rather than assuming bark density.