Roll out sheet of moss on a flat surface covered in newspaper until it lies flat. Check for and remove any imperfections. Reshape flattened or misshapen areas.
Cut the fake moss to the right size and shape for the chosen design. Use a craft knife or small garden shears to cut through the moss.
Place the planter on a piece of newspaper. Apply spray adhesive to the area of the terra cotta planter where the moss will be placed. Apply hot glue with a glue gun to the back of the fake moss.
Hold the moss around the edges, and press it carefully onto the terra cotta planter. Hold it in place for a minute, securing the moss on the planter.
Continue to apply the moss to the planter, spraying the adhesive on the planter, then putting hot glue on the moss. Let the planter sit for a few hours before picking it up, to avoid knocking off any artificial moss that is still wet.