What Does Loam Soil Mean to a Gardener?

How to Create the Ideal Soil Mixture for Your Plants

gardener with a handful of loamy soil

The Spruce / Cori Sears

Loam describes the ideal soil composition for most garden plants (although some plants require sandy, rocky, or clay soil). Loam holds nutrients and has a texture that retains water long enough for plant roots to access it, yet it drains well—meaning that the water eventually seeps away, so that plant roots do not sit in water and rot. Without quality soil, plants struggle to survive and usually require supplemental feeding and watering.

Uses for Loam

Gardeners, farmers, and homeowners highly desire loam because it's terrific for growing crops, fruits, flowers, grass, trees, shrubs, and more. Loam soil provides plants with medium-textured soil, allowing air to circulate plant roots; air circulation protects against diseases often found in poorly draining compacted soils. The soil texture allows roots to spread quickly, retain moisture, and obtain nutrients.

Good loam soil can be made using topsoil mixed with organic matter to hold moisture and nutrients. Test the soil for its pH level, nutrients, and organic matter—add lime, fertilizer, and organic matter to reach the ideal needs of your particular plant before seeding or transplanting. Tests ensure you give your plants the environment they need for germination, potting or repotting success, and proper growth.

Plants That Do Not Favor Loam

Some plants require very rocky or sandy soil; for example, root vegetables and tubers in wet, rainy climates may need fast-draining soil. These vegetables cannot sit in damp soil, or else they're prone to rot.

Other plants, like cacti, prefer light, dry soil. Loamy soil is not ideal because it may be too heavy and drain too slowly for the roots of those plants.

Loam Soil Components

Loam soil, the ideal growing medium for the vast majority of garden plants, includes three components:

  • Sand: 40 percent of the soil total by volume
  • Silt: 40 percent of the soil total by volume
  • Clay: 20 percent of the soil total

While loam can be present naturally in a garden bed, it's more likely that the native soil will need some help to achieve the ideal composition. Improving garden soil is not quick and easy, but the results are well worth it.

Types of Loam

Loam soils can be classified into subgroups: sandy loam, silt loam, clay loam, and silty clay loam. These types of loam are made by increasing the percentage of that component to make it "sandy," "silty," or to contain more "clay."

How Sand, Clay, and Silt Work Together

The sand particles are the largest among loam's three components—sand, silt, and clay. Sand does not hold moisture, but it lends good aeration and drainage as a component of loamy soil.

On the opposite end, clay particles are much smaller and are easily compacted. However, clay tends to be higher in nutrients than the other soil components. That makes clay an excellent material for building bricks but not so great for allowing water, air, and plant roots through.

Silt is a medium-sized particle with better moisture retention than sand but fewer nutrients than clay. Silt helps clay and sand mix more readily, like tempering chocolate.

In addition to providing nutrients and water effectively, loam has a loose and crumbly texture. This is referred to as being friable. Loose soil allows for oxygen to be present, which is also necessary for root growth. The friable nature of loam also makes it easy for roots to spread out to consume nutrients and water.

flower bed with loam soil

The Spruce / Cori Sears

How to Create Loam for Your Garden

Although loam combines sand, silt, and clay, adding sand to clay soil (or vice versa) will not create loam. Doing so will result in a material similar to concrete. Rather than immediately creating the correct proportions of sand, silt, and clay, improving soil is best done by adding organic matter. This nurtures soil organisms that transform the soil into a loamy mixture over time.

The decomposing organic material creates the well-draining conditions plants need. Organic matter also attracts beneficial organisms that keep the soil healthy and alive. Shredded leaves, straw, and finished compost work beautifully to create rich, loamy soil as they decompose.

Frequency for Amending Soil With Organic Matter

Creating loose, loamy, fertile soil is not a one-and-done garden task. Turning your soil into loam is an ongoing process by incorporating organic matter every year. Organic matter is quickly depleted as it decomposes, so amend the soil each season, preferably in the fall. The amount of organic matter to add depends on the balance of the soil.

Laying down a 2-inch layer of organic matter over the garden surface and then working it into the top few inches of soil should do it for most soils. However, if your soil is extremely sandy or predominantly heavy clay, it might need larger amounts of organic matter added several times a season. Instead of bagging fallen leaves in autumn, shred them and add them to your garden beds, where they will decompose and enrich the soil.

Can You Buy Loam Soil?

Buying soil in bulk can be a fast and easy way to grow your garden or yard—but it can also be pricey. In addition, while certification programs are offered to help consumers, retailers, regulators, and others identify high-quality soil, they are voluntary now.

Many companies that sell soil are obtaining that soil from construction sites where the soil has been excavated for basements or to level a yard. Generally, soil from excavation sites does not make ideal garden soil. Use that type of soil, known as "fill dirt," for other yard projects but not for growing plants.

If you intend to buy soil, compost, mulch, or other bulk garden material, know something about the company you are buying from. Don't be afraid to ask questions. Bringing in poor soil will not improve your garden and could set you back in your quest for great soil. Trusted and well-known soil companies stand behind their products.

mixing in straw to create loamy soil

The Spruce / Cori Sears

  • What is the difference between topsoil and loam?

    The difference between topsoil and loam is they both signify soil, but loam is more specific, defining a soil texture found in topsoil (the top 12 inches of soil). So while loam describes the texture of the soil, topsoil describes the location of the soil. 

  • Is potting mix loam soil?

    The difference between potting soil and loam is potting soil is made up of peat moss, perlite, vermiculite, and often, nutrients. Meanwhile, loam's composition is achieved by mixing sand, silt, clay, and organic materials.

  • How do I know if my soil is loam?

    To test if you have loamy soil: Grab a fistful of soil with a gloved hand and ball it up in your hand. It should remain in a ball shape, but if poked, it crumbles easily.

  • Is loam soil acidic or alkaline?

    Loamy soil describes a soil texture, not acidity or alkalinity. Soil additives can change a loam soil's pH. Add compost, peat moss, or sulfur to make it more acidic, or lime or bone meal to raise the alkalinity.

The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Reddy, P. Parvatha. Plant Protection in Tropical Root and Tuber Crops. Springer India, 2015.

  2. Elite Bulk Member Certification. Mulch and Soil Council.