Lettuce lichens are dual organisms that consist of a fungus and a cyan bacterium. The species is primarily found in old forests of the Pacific Northwest, growing on the sides and branches of Douglas fir trees. You can grow lettuce lichen in your garden or yard, as long as you have a cool, damp location with limited exposure to sun. You'll also need patience for these very slow growing organisms might take years to develop, depending on their prevalence in your area.
Growing Lettuce Lichen on Wood
Mix 1 pint milk, 1 tsp. flour, 1 tsp. yeast, 1/2 tsp. gelatin, 1 tbsp. green algae powder and 1/16 tbsp. of water-soluble fertilizer together in a boiler and bring to a boil. Stir the mixture frequently.
Remove the mixture from the heat and allow it to come to room temperature.
Add in 2 tsp. of lettuce lichen flakes. You can scrape the lichen off of a tree branch in your area. Add in 2 tsp. of healthy soil from the area where you removed the lichen spores. Stir the mixture well.
Immediately apply the mixture to the tree branch or log where you'd like the lichen to grow. You can use a paint brush to apply a thick coat. Do not apply the mixture during a rain shower or if rain is expected within a day.
Growing Lettuce Lichen on a Stone Wall
Mix 1/2 cup of sugar to 1 gallon of water. Make sure the sugar dissolves completely.
Pour the mixture in a spray bottle and spray it on a stone wall where you'd like the lettuce lichen to grow.
Rub lichen flakes into the crevices of the stone wall where you sprayed the mixture.