The invention describes a method and product for chelating micronutrients when used to provide the micronutrients to a plant, which comprises applying to an area of the plant or soil/substrate surrounding the plant an effective amount of a plant fertiliser composition comprising a chelating polymer having the general formula (I), capable of forming coordinate bonds with the micronutrients, transporting the micronutrients across a membrane of the plant and releasing the micronutrients for use by the plant.