Soil Horizons (Layers)

If you dug a pit and looked at the side wall, you'd see distinct layers — these are soil horizons. Each has different color, texture, and properties based on how it formed.

O horizon — Organic matter on top (leaf litter, decomposing material). Not always present.

A horizon — Topsoil. Darkest layer, richest in organic matter. This is where most roots grow and where gardening happens.

B horizon — Subsoil. Clay, iron, and minerals leached from above accumulate here. Often denser and more colorful (reds, yellows, browns).

C horizon — Parent material. Partially weathered rock. The "raw material" the soil formed from.

R horizon — Bedrock. The solid rock underneath everything.

Our soil reports show horizon data from the USDA including depth ranges, sand/silt/clay percentages, pH, and organic matter content for each layer.

Look up your address to see the specific soil conditions at your property, or browse the full glossary for more terms.