Potting soils are ideal for containers, hanging baskets and houseplants because they are lightweight, retain air and moisture and allow the roots of plants to develop in the pots. What's more, as potting soils are generally heat-sterilized, they don't contain any soil-borne diseases that could harm any kids who like poking their little fingers in dirt. Sterilizing the products also kills off any weed seeds in the mix. There are so many different brands and varieties of potting soil on the market, though, that choosing the one best suited to your needs can be a little bewildering.
Read the labels on bags of potting soil available commercially. Good potting soils should contain a lightweight mix of peat moss, perlite, shredded bark and, occasionally, sand or compost. Good potting soils will also be soil-free.
Test the contents of the bag by first lifting it to ensure it is lightweight. Squeeze the mixture inside the bag; it should have a springy texture. Avoid purchasing bags of potting soil if they are heavy in weight or if the contents can be squeezed into shapes.
Wet the potting soil when you get back home as a further test of its consistency. Take a handful of the wet mix and squeeze it. If the potting soil crumbles, leaving a residue of loose pieces in your hand, you have probably chosen a good, lightweight and soil-free mixture. If the squeezed potting mix forms into a ball and sticks together, it will contain a proportion of soil or clay. This mix will not work well in containers, as it will be too heavy and won't provide room for plant roots to grow. An exception, as recommended by Ohio State University, is potting soil for container-grown shrubs and small trees, when adding 5 to 10 percent soil or loam helps support the plant and adds to the stability of the container.
Look for potting soils tailored for specific use, if applicable, for example, soils designed for use with plants that favor acidic soils or potting soils specifically made for cacti or succulents.