One yard of mulch covers roughly 100 to 150 square feet at a 3-inch depth

The exact coverage depends on how thick you spread it. A cubic yard of mulch—the standard unit sold at garden centers and landscape suppliers—contains 27 cubic feet of material. When you spread that across your garden bed at a 3-inch depth (the depth most plants prefer), you cover about 100 to 150 square feet. If you go shallower, at 2 inches, one yard stretches to roughly 150 to 160 square feet. At 4 inches deep, it covers closer to 80 square feet.

The variation in those ranges comes from how densely the mulch is packed. Freshly delivered mulch is fluffier and covers more area. After a few weeks of settling and rain, it compacts and covers less. Heavier mulches like wood chips compact more than lighter ones like shredded bark.

Key Takeaways

  • One cubic yard of mulch at a standard 3-inch depth covers 100 to 150 square feet, depending on how tightly it settles.
  • Shallower mulch (2 inches) covers more ground; deeper mulch (4 inches) covers less, so choose your depth based on your plants' needs and your budget.
  • Freshly delivered mulch appears to cover more because it hasn't compacted yet—expect it to settle by 10 to 20 percent over the first month.
  • Measure your bed in square feet before ordering, then divide by the coverage rate for your chosen depth to find how many yards you need.

How to calculate coverage for your specific beds

Start by measuring the length and width of each bed in feet, then multiply them together to get square footage. If your bed is irregularly shaped, break it into rectangles, calculate each one, and add them together. For a circular bed, measure the radius (the distance from the center to the edge), multiply it by itself, then multiply by 3.14.

Once you have your total square footage, divide it by your target coverage. If your beds total 300 square feet and you want a 3-inch depth, divide 300 by 125 (the midpoint of the 100–150 range). You'll need roughly 2.4 yards, so order 3 yards to account for settling and uneven spreading.

If you're uncertain about depth, 3 inches is the standard for most ornamental beds and vegetable gardens. It's deep enough to suppress weeds and retain moisture, but not so deep that it piles against tree trunks or plant stems (which can cause rot). Shallow beds around young shrubs might need only 2 inches; heavily mulched pathways can go 4 inches.

Why mulch settles and what to expect over time

Fresh mulch looks generous when it arrives because the pieces haven't had time to nestle together. Within the first few weeks, rain and foot traffic compress it. Organic mulches like wood chips and bark break down slightly as they begin to decompose, which also reduces volume. By the end of the first season, you may lose 10 to 20 percent of your original depth.

This is normal and part of why mulch benefits your soil—as it breaks down, it adds organic matter. Plan to top-dress your beds each spring with a fresh 1 to 2 inches to maintain that 3-inch ideal. You won't need a full yard every year; a smaller amount refreshes the look and depth without starting from scratch.

Different mulch types and how they affect coverage

Wood chips, shredded hardwood bark, and pine straw all cover roughly the same area per cubic yard, but they settle at different rates. Pine straw is the fluffiest and settles the least. Hardwood bark is denser and compacts more. Dyed mulch is usually ground finer and compacts faster than natural bark.

Heavier materials like rubber mulch or stone don't break down, so they maintain their depth longer. However, they don't improve your soil the way organic mulch does. If you're choosing between types, consider both coverage and what your plants need—ornamental beds often benefit from organic mulch, while pathways or areas around hardscape might suit stone or rubber.

Common mistakes that waste mulch

The most common error is piling mulch against tree trunks or plant stems. This traps moisture and can cause rot or invite pests. Keep mulch 3 to 4 inches away from the base of trees and shrubs. Another mistake is spreading mulch too thin, hoping to stretch a yard further. At 1 to 2 inches, it won't suppress weeds effectively or retain moisture as well, so you end up buying more mulch sooner.

Ordering too little is also common. It's better to have a small amount left over than to run short and have to make a second trip or leave part of your bed uncovered. Most garden centers will accept returns of unused mulch, or you can store it for spring top-dressing.

How to order the right amount

Measure your beds, calculate square footage, and use the coverage rates above to estimate yards needed. Round up rather than down. When you call or visit a supplier, tell them your square footage and desired depth—they can confirm the yardage and sometimes adjust for the specific mulch type you're buying.

Ask whether the price includes delivery. For small orders (1 to 3 yards), some suppliers charge a flat delivery fee; for larger orders, it may be included. If you're picking up yourself, confirm that your vehicle can handle the weight—a cubic yard of wet mulch can weigh 400 to 600 pounds.

Frequently Asked Questions

Can I use less than 3 inches of mulch and still get weed control?

Two inches will suppress some weeds, but 3 inches is more effective. At 2 inches, light can still reach some weed seeds, and they germinate more easily. If budget is tight, use 3 inches in high-traffic areas and 2 inches in less visible spots, then plan to top-dress in spring.

How do I know if my mulch has settled enough to need more?

Check the depth with a ruler or stick pushed gently into the mulch. If it's dropped below 2.5 inches, add a 1-inch layer in spring. You don't need to remove the old mulch—fresh mulch blends in and adds organic matter as the layers break down together.

Will one yard of mulch be enough for a 10-by-10-foot bed?

A 10-by-10-foot bed is 100 square feet. One yard covers 100 to 150 square feet at 3 inches, so one yard will just barely cover it, with little room for settling or uneven spreading. Order 1.5 yards to be safe, or plan to top-dress later in the season.

Does wet mulch cover less area than dry mulch?

Wet mulch is heavier and more compact, so it covers slightly less area than the same mulch when dry. If your mulch arrives wet from rain or a truck, it may settle faster than expected. This is another reason to order slightly more than your calculation suggests.

Can I mix different types of mulch in the same bed?

Yes. Mixing types doesn't affect coverage—you still calculate based on total square footage and depth. Some gardeners use wood chips in planting areas and pine straw on pathways within the same bed. Just make sure all types are appropriate for your plants and climate.