Buying guide for Best garden soil

Written by michelle

Updated January 2025

When it comes to gardening, dirt is dirt and it doesn’t make that much difference what fills your containers, raised beds, vegetable plot, or flowerbeds, right? While many beginning gardeners make that assumption, the reality is that the proper type of soil can make the difference between a healthy, productive garden of any type and a garden filled with plants that fail to flower, produce crops, or even survive.

But because gardening centers are filled with a wide variety of bagged soils used for different purposes, it can be a little tricky to choose the one best suited to your purposes. And unless you are lucky enough to have a garden naturally filled with rich, loamy soil, chances are good you’ll need to purchase at least one bag of soil before planting new greenery or refreshing existing garden beds. But do you need garden soil? Potting soil? Topsoil? Here’s what you need to know about choosing and using the right soil or amendment for your garden.

Garden soil is used to amend the existing dirt in your garden beds.

Key considerations

What kind of dirt do you have?

Dirt, or soil, is composed of several ingredients including sand, silt, clay, water, and decaying organic materials such as fallen leaves and other plant materials as well as dead insects and other animals. Typically, dirt is also home to a wide variety of living organisms including bacteria, viruses, molds, insects, crustaceans, and worms.

While every gardener dreams of a garden naturally filled with rich, healthy loam, which is a mixture of sand, silt, and clay in balanced proportions — the ideal loam is roughly 40% silt, 40% clay, and 20% sand — along with nutrient-rich decaying organic material, the reality is that most gardeners deal with soil that is imbalanced.

• Sandy soil, which is most common in desert or arid climates as well as near coastlines, doesn’t hold water or nutrients well, making it difficult for plants not native to such soil to survive.
• By contrast, clay soil, which is common in many areas of the United States, particularly the south, tends to hold moisture too well, leading to heavy, clumped soil that drowns plant roots.
• Silt, which is formed from particles smaller than sand but larger than clay, is most common in areas near rivers, lakes, or other bodies of fresh water.

But whatever type of soil you have in your garden, it can be improved with the addition of the right supplement or contrasting soil type. Commercial garden soil is often used for this purpose.

When adding garden soil, aim for at least 2 inches of cover over the existing dirt.

Choosing the right bagged soil

Looking over the many types of bagged soil at the local home improvement center, you might wonder what the difference is between them.

Garden soil: Bagged garden soil is a blended soil containing the three basic components — sand, clay, and silt — as well as compost, which is nutrient-rich decaying organic material along with other supplements that increase the richness of the soil. Garden soil is for amending your existing garden dirt, not for filling raised beds or containers. Garden soil helps balance clay or sandy soil, improves drainage, and adds vitamins and other nutrients important to plant health.

Potting mix: This is soil formulated for use in containers. It’s designed to drain well yet hold on to enough moisture for healthy plant roots, and it contains lots of compost and other healthy organic materials.

Raised bed mix: Designed for use in raised beds that sit on top of native soil, raised bed mix is somewhere between bagged potting mix and garden soil in terms of its composition.

Topsoil: Not formulated for planting, topsoil is used to fill or level holes or other depressions in the ground.

Compost: A blend of decaying organic materials, compost is used to improve the quality of any type of soil by adding nutrients, balancing soil composition, and increasing drainage.

Soilless mix: These specialty mixes are used for starting seeds, not maintaining established plants.

Specialty soils: There are many specialty soils for specific types of plants. Examples include cactus/succulent soil, orchid soil, lawn soil, and vegetable bed soil. These are formulated to best support specific plant needs, not for general purposes.Mulch: There are many types of mulch, both organic and nonorganic but all are used as topdressings to maintain soil temperature, reduce weed growth, improve the appearance of the garden, control evaporation, and protect plant roots from freezing temperatures. Organic mulches also add nutrients to the soil as they break down.

In our reviews, we compare and contrast the differences among the various types of bagged soils, noting that garden soil is balanced for optimal nutrients and drainage for growing plants typically found in gardens.

We provide information about soil composition, as understanding the various components that make up the soil will help consumers choose the right garden soil to produce ideal growing conditions.

When we research garden soil, we check to see if contains fertilizer. This feature adds convenience to gardening, as using additional fertilizer may not be necessary.

Some garden soils are organic and made without artificial additives and chemicals. We factor this into our assessment, as we know that some gardeners prefer natural products for organic gardening.

Clay, silt, sand, and compost are the four main components of garden soil. We take this into account, noting that there are speciality varieties that are formulated for growing specific types of plants.

Some soils contain polymer crystals that store water and help keep plants hydrated, even in dry conditions. We consider this in our research.

In our guide, we provide tips for our readers to help them determine their soil type. This information will assist them in selecting the best garden soil to properly nourish their plants. We also provide information to help consumers determine how much garden soil they will need

Because many gardeners grow vegetables, they need soil that promotes growth and development. We assess garden soil for vegetable plants to help these consumers find products that will work best in their gardens.

When we choose garden soils to recommend, we advise our readers if the brands we consider tend to be compact or loose to match their plant growing needs.

In addition to providing essential nutrients to plants, another benefit of using garden soil is to improve drainage. We factor this into our evaluations of garden soil varieties.

Features

Choosing garden soil isn’t complicated, but there are a few garden soil features to consider before heading to the garden center.

Organic: While it might cost a little bit more, it’s worth it to buy organic garden soil, particularly if you are going to use the soil to improve the ground where you’ll be planting vegetables, herbs, or fruits. Organic garden soil doesn’t contain chemical fertilizers, pesticides, or other ingredients that could potentially be harmful to your health or the health of the environment.

Water-storing: While more often a feature of potting soil, there are garden soils that contain “crystals” (typically made from polymers) that swell up when exposed to water, then slowly release that water as the soil dries. This helps keep your plant roots happy and hydrated, and it is a useful feature if you live in an arid climate or just don’t want to have to water as often.

Enhanced drainage: Another feature most often found in potting soil or specialty soils, garden soils formulated for enhanced drainage typically have a bit more sand or other additives that allow water to drain faster than average soil. This is useful if your native soil contains a lot of clay or if you want to grow plants that struggle if their roots remain too wet.

Fertilizer: Many brands of garden soil include slow-release granular fertilizers that slowly dissolve over weeks or months to keep your plants green and healthy. These also reduce the need for you to apply additional fertilizer.

Vegetable gardens: Garden soil formulated for use in vegetable gardens typically contains additional compost to increase plant growth and crop production.

Tree/shrub: These garden soils are for use when planting a new tree or shrub. They typically have ingredients that help control moisture in the soil to prevent root rot or wilting while the tree establishes its roots, and most also have extra fertilizer or compost to boost tree growth and health.

Clay soil: Some garden soils are formulated with extra gypsum, which is a mineral that helps improve clay soil texture and increases drainage.

Garden soil prices

You won’t need to spend a lot on garden soil. The most common bag size is 2 cubic feet, which covers approximately 12 square feet if you are spreading the garden soil to a depth of 2 inches over the area. As a general rule, you’ll spend between $5 and $9 per bag for garden soil, with organic products or garden soils containing added fertilizers towards the higher end of that range.

Tips

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Wondering what kind of native soil you have in your garden? There are two easy ways to find out.

The simplest way to determine what kind of dirt you have is to feel it. Grab a handful of dam, not muddy, soil and squeeze it in your hand. If it forms a sticky ball, it’s mostly clay. If it feels gritty and won’t hold a shape, it’s sandy. Silty soil is somewhere between these two extremes and often has a slightly soapy feel.

For a more scientific determination of soil type, you’ll need a large clean glass jar.

• Fill the jar around two-thirds with clean water.
• Add enough dirt to raise the water level to right below the jar rim.
• Set the jar aside for a few days, leaving it undisturbed. During this time, the soil components will settle into distinctive layers.
• Examine your jar. You’ll likely see a layer of sand at the bottom, a thinner layer of grayish brown silt above that, and a top layer of brown or reddish clay, with water filling the rest of the space.
• Use a ruler to measure the combined height of all three layers of dirt.
• Now, measure each separate layer of sand, silt, and clay.
• Get out your calculator and divide each individual layer by the combined height of all three.

The results are the rough percentages of your soil’s components. For example, if the bottom layer of sand measures 2 inches, the middle layer of silt is 0.25 inches, and the top layer of clay is 0.5 inches, you have a total of 2.75 inches. Dividing each individual measurement by 2.75 gives you a rough estimate of your soil’s composition. In this example, the soil is around 70% sand, 10% silt, and 20% clay, so it’s fairly sandy soil that would benefit from the addition of garden soil containing plenty of mulch and loam.

Garden soil helps improve the quality of clay or sandy soils.

FAQ

Q. Can I use garden soil to fill my flower pots or for repotting houseplants?

A. Not if you want your plants to thrive. Garden soil is formulated for the ground, where there’s plenty of space for water movement. Used in a container, garden soil tends to compress and prevent good water drainage, leading to rotted roots.

Q. Is it really worth spending a little extra for organic garden soil?

A. While not essential, the cost difference is fairly small, and unless you are buying a very large quantity of garden soil, it’s generally worth it to buy organic. Without synthetic pesticides or fertilizers, your garden will be a friendlier place for earthworms and other beneficial critters, and any food crops, such as vegetables or herbs, won’t be potentially tainted by chemicals from the soil.

Q. How do I know how much garden soil I need?

A. Get out your calculator because you’ll need to do a quick bit of math.

• First, measure the length and the width of the garden plot where you plan on adding the soil.
• Multiply those two numbers to get the square footage of the area.
• Determine how many inches of garden soil you want to add. As a  general rule, it’s best to add at least 2 or 3 inches of garden soil to the dirt that’s already there.
• Multiply the square feet of the garden plot by the desired depth of the additional garden soil. So, for example, if your garden bed is 100 square feet and you wanted to add 3 inches of garden soil (that’s 0.25 feet in decimals), you’d multiply 100 by 0.25 for an answer of 25 cubic feet. That means you’d need 13 bags, assuming each bag contains 2 cubic feet of garden soil.