In the formal language of economics, X and Y are substitutes if the demand for X increases when the price of Y increases, or a positive cross elasticity of demand.
Potting mix is the material that goes into a garden pot before you put seeds and plants into it. 1  It keeps the plant in place. 2  It holds water for the plantâs roots to soak up.  It contains nutrients that feed the plant.
Things you need to know. In pool construction, the term gunite refers to dry mix and the term shotcrete refers to wet mix. In other contexts, shotcrete is the common term for both dry mix and wet mix. Gunite is a trademark name for dry mix shotcrete.