Soil

The Importance of Soil

Healthy soil is essential for resilient landscapes

Soil plays a vital role in supporting plant growth, improving water retention, and enhancing overall landscape sustainability. Learn how soil health, its role in ecosystems, and key nutrients can transform your outdoor spaces.

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Soil is more than just dirt, it’s a powerful force in sustaining plant life, supporting wildlife, and maintaining clean water systems. Healthy soil absorbs rainfall, reduces flooding, filters pollutants, and nourishes the organisms that enrich it.

Nature takes over 500 years to form just one inch of topsoil. Protecting this vital resource is crucial, and sustainable gardening practices can help preserve and improve soil for future generations.

Modern practices have degraded many soils, but by implementing sustainable techniques like reducing fertilizer use, improving soil structure, and adding organic matter, gardeners can rebuild soil health and enhance its benefits.

A pair of hands gently cupping a mound of black soil, shaped like a heart.

Soil Health Fundamentals

Why is soil health important?

Soil is critical to the success of sustainable gardens, and it provides important environmental benefits. Using sustainable gardening practices can help us restore the benefits that soils provide. Modern industrial society has left much of the Earth’s soil eroded, exhausted, and polluted. Many unsustainable gardening practices have unwittingly contributed to the problem. Fortunately, it’s not too late. The health of our soils can be restored and even enhanced through the implementation of sustainable gardening techniques. Nature can take more than 500 years to form just one inch of topsoil — even more reason to take care of this valuable resource!

Supporting a Strong Foundation

The role of soil in a sustainable garden

Soil is the foundation of a sustainable garden. It provides a variety of benefits that many people aren’t even aware of, including:

Rainfall absorption and flood mitigation
Removing pollutants and cleansing water
Storing water for plants, wildlife, and people
Providing habitat for organisms, such as microscopic bacteria and earthworms that transform wastes into nutrients for plants and animals
Storing atmospheric carbon
Sustaining plants, which provide food, fiber for clothing, timber, medicines, and many other goods

A person wearing white gardening gloves with yellow trim claps soil off their hands while kneeling next to a garden bed.

A cross-section of soil layers showing a dark, rich topsoil layer transitioning into lighter, compacted subsoil.

Exploring the Layers of Soil

What is soil?

Soil is a complex mixture of weathered rock and mineral particles, the living organisms of the soil food web, and the decaying remains of plants, animals, and microorganisms. Good garden topsoil is typically about 45 percent mineral particles, 25 percent air, 25 percent water and 5 percent organic matter.

Gardeners can determine the texture, structure, and pH of a given soil to properly identify its makeup and type. In doing so, exploring the characteristics of regional soils can provide helpful insights into creating more sustainably designed and maintained gardens.

Sustainable vs. unsustainable gardens

sustainable landscape	UNSustainable landscape
Soils are living ecosystems that provide the needed air and water flow to support plant growth and a healthy soil food web.	Soils are often over-compacted, which restricts the infiltration of rainwater and inhibits plant growth.
Rainfall is absorbed and replenishes groundwater supplies.	Earthworms and other organisms that make up the soil food web are greatly reduced or nonexistent due to restricted air and water movement in the soil.
Soils are protected by vegetation or mulch.	Soils are exposed to sunlight, rain, and wind.
Plants are selected that can thrive in the existing soil.	Soils require frequent amending to support healthy vegetation.
Organic matter from the landscape is used to support the soil food web and healthy vegetation.	Organic matter, such as leaves or grass clippings, is removed from the soil and disposed of off-site.