Moss graffiti, also called eco-graffiti or green graffiti, replaces spray paint, paint-markers or other such toxic chemicals and paints with a paintbrush and a moss “paint” that can grow on its own. As people become more eco-friendly and environmentally aware, the idea of making living, breathing graffiti has become a more green and creative outlet for graffiti artists. It can also be considered another form of guerrilla gardening.

Ingredients:

  • One or two clumps (about a small handful) of moss
  • 2 cups of buttermilk. You can also substitute with yogurt (vegan yogurt can be used)
  • 2 cups of water
  • 1/2 tsp. sugar
  • Corn syrup (optional)

Steps:
  1. Gather up as much moss as you can find or buy.
  2. Wash the moss to get as much soil out of the roots as possible.
  3. Break the moss apart into manageable pieces and place in blender.
  4. Add the buttermilk/yogurt, water/beer and sugar.Blend the mixture until completely smooth. You’ll want it to have a paint-like texture.
    If the mixture is at a consistency where you feel it will drip, add corn syrup until the consistency you desire is reached.
  5. Use a paintbrush to apply the moss-paint to the surface on which you wish your design to grow.
  6. If possible, check back weekly to either spray the design with water (to encourage moss growth, especially if you live in a dry environment) or apply more moss-paint.

Source: wikihow.com  & Loyal Gardener