Combine 1 cup of flour, 2 cups of active dry yeast, 2 cups of buttermilk, 2 tbsp. of corn syrup and 1 1/2 cups of moss spores in a large bucket and mix thoroughly.
Place the bucket in a sunny area for three days to ferment.
Use a paintbrush to apply a generous coat of the mixture to the outside of your concrete container.
Wrap the container with plastic wrap.
Place the plastic wrapped container in a partially sunny area for about two weeks until the moss spores begin to grow.
Water the moss regularly. This can be accomplished by either spraying the moss with a water hose or by planting flowers in the container.