When container gardening, it’s important to pay attention to what’s going into your pots. A good potting mix allows roots to flourish with adequate air circulation and holds moisture without getting soggy. Here are some dos and don’ts for choosing potting soil.
Do purchase bags that contain a mix of canadian sphagnum peat moss, ground bark, and perlite. This combo is lightweight, holds the right amount of moisture, doesn’t compact, and drains well.
Do look for brands that include a small amount of fertilizer so that you don’t have to feed your plants right away. Also look for a wetting agent, which allows organic matter to absorb water easily and evenly. Potting soil without a wetting agent is hard to rehydrate once dry.
Don’t buy bags labeled “topsoil,” “garden soil", or “cow manure.” these are heavy, compact easily, don’t drain well, and contain little if any nutrition.
Don't automatically throw away potting soil after one season. If your plants have been healthy, remove the old roots and debris. Then add new potting mix to fill the container, and blend it thoroughly with the old. However, if your plants died due to root rot or other diseases, discard the soil and start fresh.