The manufacturing site is the chlorophyll molecule.
Plants use minerals for nutrition in nature or when growing in a container.
Complex interactions involving decom- position of rocks, organic matter, animals, and microbes take place to form inorganic nutrient ions in soil water. Roots absorb these mineral ions if they are readily available. They can be 'tied up' by other elements or by alkaline or acidic soils. Soil microbes also assist in ion uptake. Even in the most well kept garden or greenhouse these conditions for uptake of ions may not exist.