Bagged potting soil usually does not contain dirt. Generally used for container gardening, it usually is a mix of peat moss, composted pine bark, and some other organic materials. Water drains out from potting soil easily. Garden soil.

Where does commercial soil come from?

Most potting soils are made up largely of peat moss, bark, and perlite. (Perlite looks like tiny white pellets; it's actually heat-puffed volcanic glass, included to keep the mixture from being too dense.) Often, potting soils are sterilized by steam to kill potentially disease-causing microorganisms.

What is store bought soil made of?

These mixes are usually a combination of peat moss, perlite, and vermiculite. It is called soil less because it does not contain organic material that might contain harmful pathogens that could harm or kill tender seedlings.