What is the difference between a mulch, a soil amendment and an organic fertilizer?
A mulch is any material placed on the soil surface to inhibit weed growth, conserve moisture and moderate soil temperature extremes. A few examples of organic mulches include wood chips, straw and pine needles. Inorganic mulches include stone, gravel and weed fabrics. Soil amendments are materials rototilled or otherwise mixed into the soil to improve its texture. Most amendments are organic, such as sphagnum peat moss, grass clippings, shredded leaves, composts, aged manure, etc. Inorganic (not originating from living plants or animals) soil amendments include perlite, vermiculite and others. Many organic soil amendments could also be considered organic fertilizers, since they contain some nutrients essential to plants. Sometimes we have to be careful with use of the word “organic”. In some contexts, it means “from a living organism”, in other cases it means “containing carbon” while others use it to mean “natural”.