Have you tried and tried to grow plants in your yard with no success? Does your grass refuse to grow thick and green no matter how well you take care of it? Don’t blame your brown thumb just yet — the real problem might be your soil type. Knowing the different soil types (and which ones are in your yard) will help you understand the problems your grass and plants are up against.
When we say soil type, we’re referring to the soil texture. All soil is a combination of organic matter (decomposed leaves, grass clippings, etc.) and weathered rock particles. The size of the particles in your soil determines the texture and soil type.
Read on to learn about the six different soil types and how to tell which one you’re dealing with.
The 6 different soil types
1. Clay soil
Clay particles are very fine, and they stick together. The result is thick, heavy soil that feels sticky. If you roll up clay soil into a ball, it will hold its shape, much like the clay used to make pottery. Also like potter’s clay, clay soil tends to dry out and bake hard in the heat of summer.
|Pros of clay soil:||Cons of clay soil:|
|✓ High in plant nutrient||✗ Few air spaces for water, nutrients, and oxygen to reach plant roots|
|✓ Retains water well||✗ Becomes waterlogged easily|
|✗ Difficult for gardeners to work with because it’s sticky when wet and rock hard when dry|
2. Sandy soil
Sandy soil is the polar opposite of clay. Sand particles are loose, so the soil doesn’t hold its shape. Because the soil particles are so loose, water, air, and nutrients can move straight through them. Sandy soils feel gritty, like sugar or salt.
|Pros of sandy soil:||Cons of sandy soil:|
|✓ Good drainage||✗ Doesn’t hold water and dries out quickly|
|✓ Easy for gardeners to work with||✗ Leaches plant nutrients|
|✓ Warms up quickly in spring, allowing for earlier planting|
3. Silty soil
Have you ever felt the slippery, soft material at the bottom of a river between your toes? That’s silt soil. Silt particles are medium-sized, somewhere in between clay and sand. Water and nutrients can move through silt particles better than in clay, but not as quickly as in sand.
|Pros of silty soil:||Cons of silty soil:|
|✓ Retains moisture without becoming water-logged||✗ Erodes easily (wind and rain carry it away because it’s very light)|
|✓ Rich in plant nutrients||✗ Can become compacted (which means water and nutrients can’t reach plant roots)|
|✓ Easy for gardeners to work with|
4. Loamy soil
Loam soil is a balanced combination of clay, sand, and silt particles. It’s the ideal soil type because the different particles work together to cancel out each other’s negative traits. Loam feels fine-textured and slightly damp to the touch.
|Pros of loamy soil:||Cons of loamy soil:|
|✓ Both hold moisture and drains well||None! “Loam” basically means perfect soil.|
|✓ Fertile and rich in nutrients|
|✓ Enough air spaces for water, nutrients, and oxygen to reach plant roots|
|✓ Easy for gardeners to work with|
|✓ Warms up quickly in spring|
|✓ Doesn’t dry out in summer|
5. Chalky soil
Chalky soil is less common than the four soil types listed above because it only occurs above underground limestone beds and chalk deposits. Chalk soil is large-grained and stony. It can be light like sand or heavy clay. You’ll often see large white lumps of stone in chalky soils.
|Pros of chalky soil:||Cons of chalky soil:|
|✓ Warms up quickly in spring||✗ Usually very shallow and doesn’t allow for deep root growth|
|✓ Can be good soil for plants that need fast drainage and alkaline soil conditions||✗ Highly alkaline because of the high calcium carbonate (limestone) content|
|✗ Drains freely, which causes drying out and loss of nutrients|
|✗ Difficult to improve with soil amendments because organic material decomposes rapidly in it|
6. Peat soil
You’ll rarely find naturally occurring peat soil in a garden setting. It usually develops in bogs and wetlands where peat moss is found. Peat soil is very high in organic matter and contains few rock particles. It looks darker than other soils and feels spongy.
|Pros of peat soil:||Cons of peat soil:|
|✓ Retains a large amount of water and nutrients for a long time||✗ Low in plant nutrients on its own (you have to add them with soil amendments)|
|✓ Warms up quickly in spring||✗ Too acidic for most plants|
|✓ Perfect for acid-loving plants||✗ Poor drainage because it holds water for so long|
Combination soil types
Think of the six basic soil types listed above as the primary colors. Just like red, blue, and yellow mix together in various combinations to create other colors, the different soil types mix together to create a diverse range of soils.
- Clay loam is almost perfect loam that contains more clay particles than sand or silt. Clay loam has the traits of loam with increased heaviness and water holding capacity from the clay.
- Silty clay is a mixture of clay and silt particles. As a combination of the two, silty clay soil has better drainage than clay on its own but also erodes faster.
- Sandy clay is soil made of mostly clay and sand particles. It is lighter and has better drainage than regular clay because of the high sand content.
Your soil could be any combination of the basic soil textures and their characteristics.
Different parts of your yard can have vastly different soil. You might have sandy soil in the front yard and clay in the back. When you test your soil type (which we’ll explain how to do in a moment), take samples from each section of the yard. Then, you can figure out where the soil is best and choose that spot to start your garden.
Tests to determine your soil type
If you can’t tell what kind of soil you have based on the traits we’ve already discussed, there are some simple at-home tests you can use to figure it out. These tests aren’t an exact science, but they should give you a general idea of your soil type.
The first test is simple. Take some wet soil and rub it around in your hands. If the soil isn’t wet, use a spray bottle to moisten it. You may be able to tell your soil type just based on what it feels like.
|How the soil feels||Soil type|
|Sticky (like potter’s clay)||Clay or a combination with high clay content|
|Gritty||Sand or a combination with high sand content|
|Soft and slippery (like soap)||Silt or a combination with high silt content|
|Fine, soft, and slightly damp||Loam or a loam variation|
|Rocky and chalky||Chalk or a combination with high chalk content|
|Spongy and damp||Peat or a combination with high peat content|
In this test, you want to see how well your soil holds together.
Hold a ball of moist soil about ½ to ¾ inch in diameter between your thumb and forefinger. Again, if the soil isn’t wet, you can use a spray bottle to moisten it until it’s about the same consistency as modeling clay. Squeeze the ball of wet soil into a flat ribbon shape sticking out past your fingers. Keep squeezing so that the ribbon grows longer until it breaks.
Having a hard time visualizing this test? Watch this quick demonstration from the University of Nebraska-Lincoln:
Once the soil ribbon breaks, measure it with a ruler or measuring tape. The length of the ribbon is an indication of your soil type. Note: This test doesn’t apply to chalky or peat soils.
|Length of ribbon||Soil type|
|No ribbon||Sand or a combination with mostly sand|
|Less than 1 inch||Loam, sandy loam, or silt|
|1 to 2 inches||Clay loam, sandy clay loam, or silty clay loam|
|More than 2 inches||Clay, sandy clay, or silty clay|
This test shows how your soil settles in water, which can help determine the soil type.
Add a handful of soil to a transparent container, such as clear plastic Tupperware or a glass jar. Add water on top of the soil, leaving at least 1 inch of free space in the container. Shake the mixture well, then leave it to settle for 12 hours.
After the 12 hours have passed, check the container to see what the mixture looks like.
|How the mixture looks||Soil type|
|Cloudy water with a layer of soil at the bottom of the container||Clay, silt, or a mix of both with high clay or silt content|
|Mostly clear water with a thick layer of soil at the bottom of the container||Sand or a mix of both with high sand content|
|Mostly clear water with distinct layers of different-sized particles at the bottom of the container||Loam or a loam variation|
|Pale grey water with white, gritty pieces at the bottom of the container||Chalk or a mix of both with high chalk content|
|Slightly cloudy water, lots of particles floating on the surface of the water, and a thin layer of soil at the bottom of the container||Peat or a mix of both with high peat content|
Other soil characteristics
Soil texture isn’t the only thing you need to know about your soil, but the other important characteristics aren’t things you can see or feel. Get a soil test to find out your soil pH level and which plant nutrients it contains (along with which ones it’s missing). You can get a soil test from your local Cooperative Extension Service.
Soil pH tells you whether your soil is acidic, alkaline, or neutral. The soil’s pH level matters for your plants because it determines which plant nutrients the soil can absorb. If your soil can’t absorb nutrients, your plants can’t take them in.
Soil pH levels are categorized as follows:
- Acidic: pH of 0 to 6.5
- Neutral: pH of 6.6 to 7.3
- Alkaline: pH of 7.4 to 14
A neutral pH is usually ideal for growing plants because most nutrients are absorbed into the soil. But there are some plants that prefer more acidic soil and some that prefer more alkaline. So, the best soil pH for your garden depends on the plants you want to grow.
Plants need many nutrients to grow healthy, and they get those nutrients from the soil. If your soil lacks essential nutrients, your plants or grass may turn weak and sickly.
Plants need more of some nutrients than others. The three categories of plant nutrients are:
- Primary nutrients: Nitrogen, phosphorus, and potassium. Plants need the most of these three.
- Secondary nutrients: Magnesium, calcium, and sulfur. Plants need less of these than the primary nutrients, but they still need a significant amount.
- Micronutrients: Boron, zinc, iron, manganese, chlorine, copper, molybdenum, nickel, and cobalt. Plants only need a small amount of these.
Most of the time, you’ll only need to worry if your soil is deficient in one of the primary nutrients.
FAQ about soil types
Loam is usually the best soil for plant growth. It combines the strengths of sand, silt, and clay without their weaknesses.
On a more technical level, there are 12 scientific soil orders to describe different types of soil around the world. Most of these aren’t relevant to you and your garden, but the 12 soil orders are as follows:
1) Gelisols: soils in permanently frozen regions that contain permafrost
2) Histosols: soils comprised mostly of organic matter; found in bogs, moors, peatlands, and similar settings
3) Spodosols: soils found in coniferous forests in wet climates
4) Andisols: soils made of weathered volcanic materials, such as ash or volcanic glass
5) Oxisols: soils in tropical and subtropical regions
6) Vertisols: soils made of expansive clay material that shrinks and swells so drastically it can damage roads and the foundations of buildings
7) Aridisols: soils found in extremely dry climates, such as deserts
8) Ultisols: acidic, extremely weathered soils found in some humid climates
9) Mollisols: soils found in prairies and grasslands
10) Alfisols: fertile soils found in some humid climates, most of the time in forests
11) Inceptisols: a diverse group of soils found in different climates and habitats, often on slopes and in mountainous regions
12) Entisols: soils that don’t fit into the other 11 orders, usually found in areas with little to no soil development, such as dunes, flood plains, landslide areas, or areas behind retreating glaciers
Soil horizons are the layers of soil extending from the surface down into the ground. From top to bottom, the soil horizons are:
— O horizon: aka humus, a thin layer of organic matter on top of the soil (not all soils have an O horizon)
— A horizon: aka topsoil, a layer composed of rock particles and organic matter; this is the layer in which plants grow and the one that’s important to you as a gardener
— E horizon: aka eluviated layer, a layer of sand and silt particles containing no organic matter, clay, or minerals
— B horizon: aka subsoil, a layer rich in minerals that filtered down from the A and E horizons
— C horizon: aka parent material, the rock material on the Earth’s surface from which the soil forms
— R horizon: aka bedrock, not actually part of the soil but the mass of rock beneath the soil
Improve your soil with amendments
Luckily for gardeners, “you get what you get, and you don’t fuss a bit” doesn’t apply to soil. While it’s true that you can’t change your fundamental soil type, you can add materials to cancel out its negative properties. Those materials are called soil amendments.
Different types of soil amendments can lighten clay, improve moisture retention in sand, or prevent erosion in silt. There are other soil amendments to balance soil pH and add missing nutrients.
Learn more about soil amendments and which one is right for you in our guide: “What Are the Different Types of Soil Amendments?”
Knowing your soil is the first step to a healthy lawn. Lawn Love’s local pros can take care of the other steps for you, from lawn mowing to weed control to leaf removal.
Main Photo Credit: planet_fox | Pixabay