Whether you are growing plants in a container outside by the patio, houseplants in pots inside the house, or are starting seeds, you never want to use a material that contains any soil or dirt from outside. You always want to use what is called a “soilless” potting mixture. The best mixes are made of a combination of Canadian sphagnum peat moss, perlite, and vermiculite. Some products will have added some slow release fertilizer or some special root microbes.
Potting mixes, or soil mixes as they are sometimes called, will fall into a fairly broad price range depending on the size of the bag and the quality of the mix. The cheaper the product, the more likely you will be buying inferior materials for your houseplant or container plant. We advise you to stay away from products the include “sedge peat”, “rush peat”, or “Michigan peat” in the potting mix. These mixes tend to hold too much water and often lead to root rot problems.