How To Test Your Yard’s Soil Texture

The soil in your yard is a mixture of minerals, micronutrients, bacteria, and decomposed organic matter. These components work together to maintain soil structure and support plant growth.

You’re probably aware that proper fertilization and pH balance are crucial to your lawn and garden’s success – but did you know that soil texture also plays a critical role in your lawn’s health?

Soil texture is determined by particle composition. The texture varies depending on the specific soil type in a region. In fact, “soil scientists have identified over 70,000 kinds of soil in the United States” alone.

This article will dive into the different soil texture classifications and how they affect plant growth. Then, we’ll go over step-by-step instructions for a soil texture test you can perform at home.

What Is Soil Texture?

Soil texture is determined by the particle makeup of a given sample. 

Soil consists of minerals that have weathered down over time to become small, sometimes microscopic particles. These particles – sand, silt, and clay – are divided into three groups called soil separates.

The particles vary in size, with clay being the smallest and sand being the largest. 

• Sand typically creates well-drained soils because of its porous, aerated structure.  However, sand is a gritty material that’s less equipped to hold essential nutrients.
• Silt is a mid-sized particle that’s good at retaining moisture and nutrients. This material is a fine powder when dry.
• Clay particles are the smallest of the soil separates. This dense, clumpy material is excellent at holding in nutrients and moisture. However, its thick structure leads to poor water and air circulation.

What Are the Different Types of Soil Textures?

Soil texture is classified by the proportion of each particle within a sample.

There are 12 classifications used to differentiate one soil texture from another. The soil texture triangle is a helpful tool for determining a soil’s composition based on particle percentages.

Here are the soil textural classes and their defining characteristics when wet and dry.

The soil texture classes have similar names because classifications are composed of the same three particle types, just in different percentages. The predominant particle type in a sample determines the soil’s class.

Many consider loam the ideal soil type because it has the most balanced silt, clay, and sand distribution. Loamy soil is the most difficult to characterize because it has qualities from each soil separate.

The Plant and Soil Sciences eLibrary provides the following particle percentages for a few soil classifications:

Why Testing Soil Texture Is Important

Soil texture is important because it determines how well plants flourish.

It affects the following characteristics that impede or boost your garden’s growth:

• Water-holding capacity is the soil’s ability to absorb and retain water.
• Permeability refers to soil drainage and the ability of air to circulate through the ground.
• Workability is the soil’s ability to be tilled, worked, and gardened.

Clay soils have good water-holding capacity but poor permeability and workability. Sandy soils have poor moisture retention but good workability and permeability. Silt soils have a moderate capability for all three characteristics.

You’ll be better equipped to plant a successful lawn and garden if you fully understand your soil’s texture. 

Some gardeners analyze soil texture by feeling the dirt and considering the present particles, textures, and shapes. The USDA Natural Resource Conservation Service provides an in-depth guide to soil texture by feel. 

Don’t worry if you don’t reach a conclusion with the touch test. You can determine your lawn’s texture and particle percentages with the DIY soil test we’ll explain next.

What Is the Jar Test?

The jar test is an easy way to determine your lawn’s soil texture using a few items around your house. You can buy a soil texture test kit online for around $10, but we recommend trying this DIY test first. It’s cost-effective, and you won’t have to leave home to complete it.

With the jar test, you’ll discover the proportions of silt, sand, and clay in a soil sample by seeing how quickly each particle group settles in a container of water.

This method is sometimes called the sedimentation test because it illustrates how particles of varying sizes and densities settle at different rates. 

Materials Needed to Do a Soil Texture Test

You’ll need the following materials to complete the jar test:

• Small garden trowel or spade
• 2 cups of soil sample
• Quart-sized mason jar (preferably straight-sided)
• Heaping tablespoon of powder laundry detergent
• 2-3 cups of water
• Permanent marker

How to Test Soil Texture

Follow the step-by-step instructions below to complete the sediment test and measure your soil’s texture:

1. Use your shovel to remove the top layer of grass from the area you’d like to sample.
2. Dig up a wedge-shaped soil sample.
3. Collect the center of the wedge to produce two cups of soil. Remove any rocks, sticks, or other debris from the sample.
4. Place your soil sample in a straight-sided glass jar. 
5. Add a heaping tablespoon of powder laundry detergent to the sample. This product will help the soil particles disperse.
6. Fill the jar with water and tightly secure the lid.
7. Shake the closed jar for five minutes.
8. Set the jar on a level surface.
9. Allow the first group of particles to settle at the bottom of the jar. After one minute, mark the top of the settled soil with a permanent marker. This is your soil’s proportion of coarse sand particles. 
10. Wait 30 more minutes, then make a new mark at the top of the settled soil. Subtract the depth of the sand from this new measurement to get your silt layer depth. 
11. Wait until the next day to mark your final sediment depth. The last measurement minus the silt and sand layer depths will be your clay layer. 
12. Finally, determine each particle’s percentage by dividing each measured depth by the total soil depth and multiplying that number by 100.

Once you’ve completed the jar test and found the percentage of each particle, you can reference the soil texture triangle to determine your soil’s texture classification.

Next Steps

After deciding your yard’s texture with the soil test results, you can assess which soil amendments will best serve your lawn’s health and plant growth.

If your soil contains a high clay percentage, it might need amendments to improve permeability and water drainage. Clay is a dense substance that can suffocate plants’ roots.

The NC Cooperative Extension suggests adding organic matter to clay soil to “discourage compaction, add nutrition, improve drainage and aeration, moderate soil temperature, and provide pore space” essential for plant growth.

If your lawn has a high sand content, consider adding a three-inch layer of mulch to garden soil. Mulch keeps plants’ roots cool and helps the ground retain moisture. It also decays gradually to provide shifty soil with a steady supply of nutrients.

Some silt soils are relatively loose, which leads to poor nutrient absorption. Add a layer of organic matter to these soils to improve water retention and workability.

Final Thoughts

Like nutrient distribution and proper pH balance, texture is an essential component of healthy soil. You can use a test kit or perform the jar method to determine the textural classification of your lawn. 

Once you know the composition of your yard, you can make the amendments necessary for maintaining flourishing plant growth and sustainable soil structure. You’ll be one step closer to a greener, happier lawn and garden by supporting your soil where it falls short.