The 6 Types of Soil For Your Garden

I’ve lived and gardened in a lot of places, from Florida’s thin, chalky-limestone ground to Utah’s iconic red-clay earth. In that time, I’ve learned one hard lesson: Unless you want to harvest a big basket of disappointment, you have to know your soil.

With advice from three experts, here’s how to figure out what kind of soil you have, so you can determine its strengths and weaknesses and how to amend it so your plant species of choice will thrive .

About the Experts

Hannah Gibbons is a garden educator with a decade of experience in the agriculture industry. She works at Sow True Seed, which is an employee-owned seed company that specializes in open-pollinated and heirloom seed varieties for home gardeners.

Misti Mathis is co-owner of Harvest Gold Organics, the result of a six-year collaboration with agronomists to create a sustainable tool for water conservation and soil remediation.

Cynthia Domenghini, Ph.D, is an instructor and horticulture extension specialist at Kansas State University. She writes a weekly horticulture newsletter to support gardeners across the state of Kansas.

What Is Soil?

Soil is organic material on the surface of the Earth, the foundation for growing strong plants. Soil anchors them, provides nutrients and stores water so they can grow.

It takes years, even millennia, for soil to form from weathering rocks and decomposing organic matter. The type of soil you have depends on where you live, and what geologic and ecologic forces created it.

Don’t confuse soil with dirt. “Soil is a dynamic ecosystem composed of minerals, organic matter, air, water and countless organisms,” says Mathis. “Rich, well-draining soil allows plants to produce strong roots.”

Types of Soils

Sandy soil

This type is known for a course texture and large particle size, and it drains quickly. It warms up early in the spring and can be easy to cultivate. But it doesn’t hold water or nutrients well.

“Sandy soils are great for growing melons!” says Gibbons. “They can also be really acidic, which makes them great for blueberries or certain hydrangeas.”

Silty soil

With a particle size between sand and clay, silty soil is slippery (not sticky) when wet. It gives a good balance between retaining moisture and nutrients, while also draining well. “The Fertile Crescent [in the Middle East] is filled with silty soils,” says Gibbons.

However, Gibbons says, “Silty soils can be easily compacted. So if you’re lucky enough to be growing in it, avoid stepping in garden beds or over-tilling.”

Clay soil

Clay offers the smallest particle size. It’s also smooth but sticky when wet, and dense with poor aeration. It holds nutrients, but doesn’t drain readily and takes longer to warm up in the spring. “When growing in clay soils, consider plants with rot-resistance or large stubby roots that can hold their own,” says Gibbons.

Loamy soil

Loam generally contains a balanced mix of particle size, but can lean toward sandy or clay-like. “Loam is the ideal texture for gardening,” says Domenghini. “It has the best drainage, water holding capacity, nutrient availability and pore space to support plant growth.”

Peaty soil

This is made primarily from decomposed organic matter. It contains little sand or clay, is moisture rich, acidic and really fertile. Peaty soil is relatively rare in the U.S.

Chalky soil

Chalky or lime-rich soils range from gravely to clay textures. They’re high in calcium carbonate (often from weathered limestone), which makes them alkaline. That lime adds nutrients, but too much can hinder plant growth.

How To Tell What Type of Soil You Have

You can feel the texture of your soil and look for clues like:

• Particle size;
• How quickly it drains;
• What plants thrive naturally.

It’s also a good idea to test the soil’s pH and nutrient levels, and contact your local gardening extension office for advice. Also, try this test from Domenghini:

• Sift rocks and debris from a handful of soil.
• Dry the soil in a 150-degree oven for a few hours.
• Grab a handful of the dried soil and add water to shape it into a ball.
• If the soil feels coarse or gritty or won’t shape into a ball, it has a high sand content. If it’s sticky, it’s clay.

“Press the soil between your thumb and pointer finger shaping it into a ribbon that is just a few millimeters thick,” says Domenghini. “The longer the ribbon is the more clay you have in your soil.”

What Type of Soil Is Best for Gardening?

Loamy soil is ideal for the widest variety of plants because of its good drainage, aeration and ability to hold nutrients. However, silty and peaty soils are also excellent. “But keep in mind, your native plants grow best in your native soil,” says Gibbons.

How To Amend Soil

Your soil type and what you want to grow will determine the best amendments. You’ll almost always need to add organic matter or soil conditioner to improve soil texture and nutrients.

“Organic matter helps to improve the drainage of soils high in clay content, while also improving water holding capacity of soils higher in sand content,” says Domenghini.

FAQs

What’s the difference between topsoil and garden soil?

Topsoil is the uppermost layer of soil, rich in organic matter and vital for plant growth. Garden soil, Mathis says, “is a broader term encompassing any soil suitable for gardening, which may or may not include topsoil.”

What is the best soil for a vegetable garden?

For vegetables, acidic soil with a pH of 6.0 to 7.0 is considered ideal. Flowers often prefer neutral or slightly alkaline soil, with a pH of 7.0 to 7.5.

Can I use garden soil in a pot?

Yes. But it’s not a great idea because garden soil is denser, so it won’t drain well.

“Potting mix is intended for container gardens and is sometimes called ‘soilless mix’ because it does not actually contain soil,” says Domenghini. “It is a mixture of peat moss and other organic materials specifically blended to provide the right amount of airspace and water retention for container-grown plants.”