Topsoil is the uppermost layer of soil, usually spanning two to eight inches below the earth's surface. It is nutrient-dense, giving it a darker color than subsoil, and contains the highest concentration of organic matter and microorganisms among all soil types. This layer is where the majority of plants grow their roots.
Topsoil Uses
The most common uses for topsoil include:
- Fill in barren spots in the ground
- Create new or elevated garden or vegetable beds
- Improve drainage
- Provide a nutrient-rich base layer for sod or grass seed
- Proper surface grading near residential buildings
Types of Topsoil
These three types are usually found in different ratios in most soils.
Sandy Loam
This material is usually made up of roughly 40 percent silt, 40 percent sand and 20 percent clay. It will hold nutrients and moisture around a plant's roots without leaching its nutrients, draining too quickly or becoming water logged, making it the most popular choice among gardeners.
Clay Soils
This material is fertile but is prone to "water logging," creating less favorable conditions for plants or vegetation to thrive.
Sandy Soils
This soil drains well, but also enables plant nutrients to be washed out or leached as a result.