An object of the present invention is to provide a method for producing a plant in order to obtain a plant having a high content of a caffeoylquinic acid compound. Another object of the present invention is to provide a method for producing a processed plant product. The method for producing a plant according to the present invention includes a step of growing at least one plant selected from the group consisting of a tuber other than a sweet potato, a plant belonging to the family Convolvulaceae, and a plant belonging to the family Asteraceae； and a step of subjecting the grown plant to nutriculture using a culture solution which is substantially free of a nitrate ion and a phosphate ion.
