To provide a method for producing a plant culture bed comprising used-paper charcoal allowing a user to freely design open pore spaces where the root systems of plants develop.

The method for producing a plant culture bed comprising used-paper charcoal comprises adding water to shredded used paper, kneading the mixture to prepare paper clay material, and carbonizing the prepared material. In this method, pore space forming members made of elastic material such as vegetable jelly having water as a dispersion medium is added to the paper clay material so as to be dispersed, and the water is vaporized in a carbonizing process so as to form a lot of pore spaces where the plant roots develop, in the used-paper charcoal.