A yard of mulch covers about 324 square feet at 1 inch deep
One cubic yard of mulch—the standard unit you'll order from a landscape supplier—covers roughly 324 square feet when spread 1 inch thick. That's the math: a cubic yard is 27 cubic feet, and 27 cubic feet spread across 1 inch of depth equals 324 square feet. The catch is that depth matters enormously. Most landscapers spread mulch 2 to 3 inches deep for weed suppression and moisture retention, which means the same yard covers only 162 square feet at 2 inches or 108 square feet at 3 inches.
The depth you choose depends on what you're trying to accomplish. A thin 1-inch layer looks sparse and won't suppress many weeds. Two inches is the practical minimum for garden beds and around shrubs. Three inches is standard for new plantings or areas with heavy weed pressure. Anything deeper than 4 inches can trap moisture against plant stems and cause rot.
Key Takeaways
- One cubic yard of mulch covers 324 square feet at 1 inch deep, 162 square feet at 2 inches deep, and 108 square feet at 3 inches deep.
- Most homeowners spread mulch 2 to 3 inches deep, so a single yard typically covers between 108 and 162 square feet in actual practice.
- Depth affects both appearance and function—too thin and weeds break through, too thick and you risk moisture problems near plant stems.
- Measure your bed area in square feet, decide on your target depth, then divide to find how many yards you need.
How to calculate mulch needed for your beds
Start by measuring the length and width of each bed in feet, then multiply to get square footage. A bed that is 10 feet long and 4 feet wide is 40 square feet. If you have multiple beds, add them all together. Write down your total square footage and your target depth (1, 2, or 3 inches).
Use this straightforward table to find how many yards you need:
| Depth | Square feet per yard | Example: 500 sq ft bed |
|---|---|---|
| 1 inch | 324 sq ft | 1.5 yards |
| 2 inches | 162 sq ft | 3.1 yards |
| 3 inches | 108 sq ft | 4.6 yards |
For a 500-square-foot bed at 2 inches deep, divide 500 by 162 to get 3.1 yards. Most suppliers will round up, so you'd order 3.5 or 4 yards. It's better to have a little left over than to run short and need a second delivery.
Why depth varies and what it means for your order
Landscape contractors often recommend different depths depending on the situation. In established beds where you're topping off old mulch, 1 to 2 inches is enough because there's already a base underneath. In new beds or areas with aggressive weeds like crabgrass or bindweed, 3 inches gives you better suppression. In very shaded areas where decomposition is slow, you can go thicker without as much risk of rot.
The depth also affects how often you'll need to reorder. Mulch breaks down over time—wood-based mulches typically lose about half their volume in the first year as they decompose and settle. If you spread 3 inches in spring, by the following spring you might have only 1.5 to 2 inches left. Knowing this helps you plan whether to refresh every year or every other year.
Common mistakes that waste mulch
The most common error is spreading mulch in a thick volcano shape around tree trunks and shrub stems. This traps moisture and can cause rot, canker, and pest damage. Mulch should sit 3 to 6 inches away from any stem or trunk, creating a donut shape rather than a cone. This doesn't change how much you order, but it does change how you place it.
Another mistake is ordering by the bag when you have a large area. Bagged mulch costs roughly three to four times more per cubic yard than bulk mulch delivered by truck. For anything larger than about 100 square feet, bulk delivery saves money even after accounting for the delivery fee. A typical bulk delivery costs $40 to $75 for the truck, but you're getting mulch at $25 to $40 per yard instead of $60 to $100 per yard in bags.
How mulch settles and compacts over time
When mulch is first delivered and spread, it sits loose and fluffy. Over the first few weeks, it settles as it absorbs water and as foot traffic compacts it. You may notice your 3-inch layer looks more like 2.5 inches after a month. This is normal and expected. The settling actually helps—it closes gaps where weeds can poke through.
As mulch decomposes, it also shrinks. Wood chips break down faster than bark nuggets; shredded hardwood breaks down faster than pine. By the end of the first growing season, you'll have lost some volume. This is why many homeowners add a thin refresh layer—about 1 inch—each spring rather than replacing everything. It's cheaper and less disruptive to plants than a complete redo.
Mulch types and how they affect coverage
Different mulch materials have slightly different densities, which can affect how far a yard stretches. Shredded hardwood and cypress tend to be denser and may cover slightly less area per yard. Pine bark nuggets and wood chips are lighter and fluffier, so they may cover slightly more. The difference is usually small—within 10 percent—so the 324-square-foot rule at 1 inch is a reliable starting point for any wood-based mulch.
Rubber mulch and colored mulches (dyed wood chips) are denser and heavier, so they settle faster and may cover a bit less area. If you're using one of these, order about 10 percent extra to account for settling. Stone and gravel don't decompose, so they hold their depth much longer, but they also don't improve soil the way organic mulches do.
Ordering and delivery logistics
Most landscape suppliers sell mulch by the cubic yard, with a minimum order of 3 to 5 yards depending on the company. Some offer delivery for orders over a certain size; others charge a flat fee. A few will deliver as little as 1 yard, but the per-yard cost is higher. Call ahead and ask about their minimum, delivery cost, and whether they can spread it for you (some do, for an extra fee).
When the truck arrives, the driver will typically dump the mulch in one pile at the edge of your property. You'll spread it yourself with a shovel or rent a wheelbarrow. If you have a large area or physical limitations, paying for the driver to spread it is worth the cost—it usually runs $50 to $150 depending on the area and depth.
Frequently Asked Questions
Do I need to remove old mulch before adding new mulch?
No. If the old mulch is still in decent shape and hasn't compacted into a hard mat, you can spread new mulch right over it. This is called topping off. If the old mulch is matted, moldy, or more than 4 inches deep, remove the top layer first. Removing everything and starting fresh is rarely necessary unless you're dealing with a disease or pest problem.
What if my bed is an irregular shape?
Break it into rectangles and measure each one separately, then add the square footage together. A curved bed can be approximated as a rectangle slightly smaller than its actual bounds—this gives you a conservative estimate and you'll have leftover mulch, which is better than running short.
Can I use mulch in vegetable gardens?
Yes, but use caution. Hardwood mulch and bark chips work well in vegetable beds because they break down slowly. Avoid dyed mulches and rubber mulch in edible gardens. Keep mulch 6 inches away from vegetable stems to prevent rot and pest issues. Spread 2 to 3 inches deep between plants.
How long does mulch last before I need to replace it?
Wood-based mulches typically last one to two years before they decompose significantly. After the first year, you'll notice it's thinner and darker. Many homeowners add a 1-inch refresh layer each spring rather than replacing everything. Bark nuggets last longer than shredded wood; pine lasts shorter than hardwood.
Is there a difference between mulch sold by the yard and mulch sold by the ton?
Yes. Mulch sold by the cubic yard is a volume measurement. Mulch sold by the ton is a weight measurement. The same cubic yard of mulch can weigh different amounts depending on moisture content and material type. Always order by the cubic yard for landscaping purposes—it's the standard measurement and makes coverage calculations straightforward.