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.
wackymack Well-Known Member. make your own mix of soil,it should have an organic smell to it that has a airy texture and that denses up when wet,u should use the same soil for the whole grow as well as one pot if possible,a 1-3 gal pot will do just nicely.