Method for increasing the content of useful components in plants at least partially edible characterized in applying to the plant at least: - an aqueous solution of zinc ions - an aqueous solution of magnesium ions. Such solutions are applied in one or more application cycles each comprising at least the spraying of the zinc aqueous solution onto the epigeous portion of the plants and the spraying of the magnesium aqueous solution onto the epigeous portion of the plants, said applications being carried out in different and disjointed periods oftime.
