Earthworm castings tea, also known as vermicompost tea, is made from the droppings of earthworms mixed with composted organic matter from a worm bin. The mixture is soaked in water with periodic stirring to create a nutrient-rich solution. The tea is used as a fertilizer in gardens and on houseplants. This process requires a 10- to 12-cup coffee filter, twine and a watering can.
- Make a vermicompost tea bag
Pour 1/4 cup vermicompost mixture from your worm bin into the center of a 10- to 12-cup coffee filter. Gather the filter closely together at the open side, and tie it tightly with a piece of twine.
- Soak the tea bag
Place the tea bag in a 1-gallon watering can, and fill with water. Leave about an inch free at the top to facilitate stirring.
- Steep, and stir the tea
Let the tea steep for at least eight hours, stirring frequently. The stirring aerates the water. Proper aeration encourages the growth of helpful microbes.
- Feed the vermicompost tea to plants
Use the tea to water plants once every seven to 10 days. Apply the solution with the watering can or spray bottle, or use a hose-end sprayer for large garden applications. In addition to adding beneficial nutrients and microbes, the fertilizer also reduces powdery mildew. Vermicompost tea is a safe, organic fertilizer that does not burn plants.