The simple definition of a plant hormone is that it is a molecule that at micromolar or lower concentrations acts as a messenger between plant cells. The phytohormones have the ability to regulate many aspects of plant growth and development from seed germination trough senescence and death of the plant. More than 60 years ago the first plant hormone auxin was discovered. Since then five additional classes of plant growth regulators has been recognised: gibberellins, cytokinins, brassinosteroids, abscisic acid, and ethylene. Most recently strigolactones, salicylates, and jasmonates are beginning to gain acceptance as new classes as plant growth regulators. With time their commercial use for research purposes became a reality due to the OlChemIm supply advertised at these web sites. Their use in agriculture has also a great deal of potential and with time their commercial use for these purposes may become a reality.