Landscape professionals often call topsoil fill dirt – but it's really not actual dirt. Dirt is what you find when you excavate a basement or attic. No plants thrive in dirt. Topsoil, on the other hand, contains natural organic matter from leaves, grasses, weeds and tree bark that can help sustain plant life.

What is the source of topsoil?

The topsoil layer is a mixture of sand, silt, clay and broken down organic matter, called humus. Humus is rich, highly decomposed organic matter mostly made from dead plants, crunched-up leaves, dead insects and twigs. Topsoil is the home of living things and the materials that they make or they change.

Is bagged top soil any good?

A. Bagged soil can vary enormously in quality, but the fine print on the bag can provide clues. Some products labeled "top soil" are, contrary to the name, not good for planting. ... Mixing some of either with the bagged top soil increases the likelihood of achieving an excellent soil mix for your plants.