Commercial

• A wide variety of commercially prepared potting mixes line the shelves of garden centers and nurseries. If you use commercial preparation, make sure you select a product that works well for the particular plant you're growing. For example, a rapidly growing plant needs plenty of moisture, so you will want a potting mix that holds a lot of water. For a slow growing plant or a plant that thrives in drier conditions, you will need a mix that holds less moisture.
  
  

Homemade

• You can make your own potting mixes rather than purchase a commercial preparation. The North Dakota State University Extension recommends the following mixture: 1/3 garden soil,1/3 peat moss and 1/3 sharp sand. Never use garden soil in a potting mix unless it is sterilized to eliminate any bacteria or insect larvae. To sterilize garden soil, put it in the oven and bake for 20 to 30 minutes at 180 degrees Fahrenheit. Make sure you wash any equipment you use in a chlorine-bleach solution afterwards, advises Purdue University.
  
  

Artificial Mixes

• You can also purchase potting mixes that contain no garden soil at all. Called artificial mixes, this type of media typically consists of some non-soil organic matter, such as peat moss or pine bark and some inorganic materials, such as perlite or vermiculite. An artificial mix formula recommended by the Virginia Cooperative Extension is as follows: one part shredded sphagnum peat moss, one part perlite, one part vermiculite and 1/2 cup ground agricultural limestone.
  
  

Repot

• When you repot a plant you should also replace the potting mix. Make sure you water generously after adding the new mix. When the plant has grown to the desired size, do not repot. Simply take some of the potting mix off the top of the pot and replace with new media. Do this at least once every year, advises Purdue University.