Potting soil is used for container gardening or for houseplants. Potting soil, though, isn't actually soil. Potting soil is made up of composted materials, peat moss, vermiculite and perlite, sand and limestone. This basic mix is a soil-less potting soil; however, some potting soils will contain a garden soil to provide nutrients to the plant. You use potting soil to anchor your plants within a container. The soil acts as a medium for the water and fertilizer you add to the container to feed your plant.
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