Pour 2 cups of flour, 2 to 3 cups of chopped moss spores and 9 teaspoons of active dry yeast into a large bucket. Mix together with a wooden spoon.
Pour 4 cups of buttermilk and 4 tablespoons of corn syrup into the dry mixture in the bucket and mix thoroughly with a wooden spoon.
Cover the bucket with plastic wrap and set it out in the sun for at least three days or until it begins to smell pungent.
Use a clean paintbrush to spread the mixture over the entire clay pot or in small areas where you want moss to grow.
Wrap the pot in plastic wrap and set it in an area that will get partial sun during the day. Your pot will begin to grow moss within 2 weeks. Remove the plastic wrap when your pots have grown the amount of moss you desire.