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How Many Bags of Mulch Is Needed in A Yard?

How Many Bags of Mulch Is Needed in A Yard?

The best thing you can do for your garden this year is to add a layer of mulch to your planting areas.

Sure, you’ll be hot and tired long before you finish the task but mulch, on the other hand, has a significant payoff.

Some benefits of mulching include beautiful beds, fewer weeds, and healthier plants.

Before you get out all your gardening equipment, roll up your sleeves, pull on your garden boots, and get started, here’s everything you need to know about how many bags of mulch in a yard are necessary for optimal plant growth.

What is mulch?

Mulch comes from bark, leaves, or compost and is used to cover the soil around plants. Part of garden maintenance is knowing what mulch is and how many bags of mulch in a yard you need to protect plant growth.

According to a horticulture instructor at Penn State Extension, β€œβ€¦one of its main benefits is that it helps preserve moisture in the soil by acting as a barrier to evaporation. It also eliminates weeds and increases organic matter in the soil, making beds easier to maintain.”

Additionally, the mulching process keeps the soil wet, reduces weeds, keeps the ground cool, avoids frost heave in the winter, and improves the appearance of the garden bed.

As the organic mulch decomposes, it improves the soil’s structure, drainage, and nutrient-holding capacity.

So, how do you decide where to mulch?


Mulch helps keep the roots of new plants, annual or perennial plants, moist while they establish themselves. Mulching is also vital for the health of blooming shrubs, vegetable gardens, and even container planting.

Mulch protects tree trunks from string trimmers and mowers. Just don’t build a “mulch volcano” by piling it up against the trunk. Moisture and rot thrive in this environment.

The best bags of mulch to use are any natural product that decomposes over time, such as bark, wood chips, or pine needles, which is organic mulch. Straw is also an excellent choice for vegetable gardens.

Replace mulch as needed, generally once a year for fine or shredded varieties and every two to three years for coarser types such as bark chips. The color of the mulch to use is a matter of personal preference.

Why do I need it?

Why do I need it?

Mulching is essential to plants for various reasons. This article highlights the benefits of mulching in the garden, which include:

  • During a drought, mulching is critical to your landscape’s survival. Mulch reduces the quantity of water that evaporates from your soil, lowering the amount of water your plants need to flourish.
  • Mulch improves the condition of your soil by breaking up clay and enabling more water and air to flow through the ground. Mulch also adds nutrients to sandy soil and increases its water-holding capacity.
  • Mulch works as an insulator on top of the soil, allowing it to stay cooler in the summer. Cool earth optimizes root growth which increases robust plant growth.
  • Mulch keeps weeds at bay, making it much easier to pull any that do emerge. Minimizing weed growth appeals to all gardeners!
  • Mulching improves the fertility of the soil. Minerals and plant nutrients are part and parcel of mulch materials. In addition, some nutrients from the mulch are washed into the ground when it rains. This natural decomposition process enhances the soil’s structure, increases nutrients for growing plants, and consequently boosts the soil’s fertility.
  • Mulch is very beneficial to crops like tomatoes, melons, and cucumbers, and many others. Because the mulch acts as a barrier between the dirt and plant foliage, it reduces the chance of fungal and other diseases forming.

How much mulch do I need?

It might be challenging to know how many bags of mulch in a yard to buy and how deep to spread it in your pots and beds. So here’s how to figure out how many bags of mulch are necessary to ensure enough coverage and a healthy lawn.

To determine how many bags of mulch in a yard you need, calculate the square footage of the area you want to mulch. Break up an extensive landscape into a succession of rectangles, circles, and triangles to make the procedure easier.

The first action is to multiply the width by the length to establish the size of a rectangular space. Next, multiply the base by the height and divide by two if the area is triangular.

Multiply radius x radius x 3.14 for circles. If the space you’re measuring is oddly shaped, divide it into smaller, more manageable chunks.

For example, figure 8 is in the form of two circles, an L is in the form of two rectangles, and a curved corner bed is a sequence of triangles. Then sum the square footage of all the areas together.

Convert the area in square feet to the amount of mulch in cubic feet after establishing the square footage of the area needing mulching.

To do so, you’ll need first to choose how deep you want to mulch the area. Compost is common as mulch, with a depth of 1 to 2 inches. The thickness of wood mulch and bark materials should be 2 to 4 inches.

Measure the space using square feet by the depth you want to mulch (use a fraction or decimal of afoot.

  • 1 inch = 1/12, or .083 foot
  • 2 inches = β…™, or .166 foot
  • 3 inches = ΒΌ, or .25 foot
  • 4 inches = β…“, or .33 foot

Depth matters

epth matters

The depth of mulch is also a crucial factor to consider when mulching. A 2-inch layer of organic mulch is optimal for retaining moisture and suppressing weeds. But don’t overdo it, as this is one instance when more isn’t always better.

Plant roots require oxygen to thrive, and a layer of mulch that is too thick will smother the roots. It will also cause water to run off the top of the mulch rather than filtering through and soaking into the soil below.

The depth at which to mulch should entail the following factors:

  • Mulch with a fine texture, such as shredded hardwood, should be no more than 3 inches thick.
  • Coarse textures, such as pine bark nuggets, allow for increased air movement so that you can increase the number of layers to 4″ depth.

Calculate the size of your bed in square feet. For square or rectangular beds, multiply the width by the length of the area.

For round beds, multiply the radius (distance from the center to the edge of the bed) by its own figure and then multiply the total by 3.14.

It’s important to remember that bags of mulch cater to cubic yards. One cubic yard of the material is enough to cover a 324-square-foot area with an inch of depth. So, multiply your square footage by the required depth in inches, then divide by 324 to get your total.

Here’s your formula: Square footage x desired depth / 324 = cubic yards needed.

How to calculate?

How to calculate?

To answer the question, how many bags of mulch in a yard, these formulas will give you the answers for rectangular and circular yards.

This formula includes:

Rectangular garden

This calculation begins by measuring the length and breadth of the bed in feet for square or rectangular beds. To get the size, or square footage, of your garden bed, multiply these two values. Consider the following scenario:

  • For example, the length of the garden is 20 feet.
  • 15-foot garden width
  • 300 square feet = 20 x 15 Equals square footage

Then you need to figure out how deep you want to pile the mulch. For most vegetable gardens or flower beds, a depth of two to three inches is usually sufficient.

Multiply the square footage of your bed by the depth you want it to be. With the preceding example and a 3-inch depth (0.25 feet), the total amount of mulch required is 300*0.25 = 75 cubic feet.

Round garden

Measuresure the diameter, or the number of feet across, to get the area. To obtain the radius of your bed, divide this in half.

The radius should now be square or multiplied by itself. You get the square footage by multiplying this figure by pi, or 3.14.

Consider the following scenario:

  • 14-foot garden diameter
  • The radius of the garden is 14 2 = 7 ft.
  • 7 x 7 = 49 feet is the square of the radius.
  • 49 x 3.14 = 153.86 square feet

Because The dirtbag offers mulch by the cubic yard, the final ep is to convert your desired square footage of mulch into cubic yards.

To convert, double your amount by 27, as one cubic yard of mulch equals 27 cubic feet. Then, to figure the number of bags of mulch, you’ll need to cover your soil, round up to the nearest whole number.


From these details, it should be simpler to calculate how many bags of mulch in a yard is necessary to boost plant growth.  

A gardener can determine the number of bags of mulch needed by considering the garden’s shape, size, and depth.

The easy calculation steps highlight how many bags of mulch in a yard is necessary per cubic feet of the area, and you also have an idea of how deep to mulch.

Purchasing your next mulch needs (or making your own) should now be a lot easier.