worm casting tea

How To Make Worm Casting Tea

Have you ever heard of worm castings? They’re solid gold for gardeners and farmers alike. Gardeners love to sea worms in their soil because it means they get free worm castings! How can you beat a deal like that? That’s not where the fun ends, though. Did you know you can make worm casting tea?

What nutrients are in worm castings?

Worm castings are extremely nutrient-rich, more so than just your standard compost. As a result, it doesn’t need to be spread as heavily or as often as compost. This type of manure has an NPK rating: 5.5.3. What nutrients are in worm castings?

  • Iron
  • Sulfur
  • Calcium
  • Nitrogen
  • Phosphorus
  • Potassium

What are the benefits of worm casting tea?

One way to infuse your garden with worm castings is by simply spreading about 1/2 cup of castings pere 100 square feet of garden space. This method takes a bit of time, though, as the castings need to be slowly broken down by natural forces, like rain. Making worm casting tea quickly replicates this process, breaking down the castings and making it easier for their contents to soak deeper into the soil.


Worm casting tea improves and enhances your soil by introducing beneficial microbial lifeforms that make healthy soil, increase the yield of your crops, improve your soil’s ability to hold water, and make both plants and the soil itself resistant to diseases that can harm your plants. Amazing!


Is worm casting tea safe?

Worms are known to harbor pathogens that can make humans sick, including salmonella and E. coli. It is not terribly likely that you will come into contact with and ingest these pathogens during normal, routine use of worm castings. However, there is a non-zero chance that you could come into contact. So take extra precautions, like wearing gloves, when handling worm castings, and always wash your hands afterward!


How much should I make?

How much worm tea you should make is determined mostly by the size of your garden. My recipe makes 5 gallons total, but remember: even if you don’t use all of your worm casting tea at once, you can store it in a bucket with a lid for later use or share it with friends and neighbors. I generally apply one cup of casting tea to each individual plant, but you don’t have to be as scientific or precise. You can just as easily dump your tea around your garden haphazardly – there is a low likelihood this will cause problems.


Making worm casting tea

Worm casting tea is so easy to make – the time sink is maybe 5 minutes of active work and then 24 hours of waiting. Here’s what you do:

  1. Measure out two cups of worm castings
  2. Dump the manure into a 5 gallon bucket of water
  3. Allow the castings and water to steep together overnight, ideally for 24 hours
  4. Once the castings have mostly dissolved and the water is a darker color, you can apply the tea to your plants.
  5. Apply at least one cup of tea to each plant.

This process can be repeated, though we advise that at most, you should apply castings or casting tea every 2 months at most.

Thomas Nelson
Environmental Advocate
Thomas is an environmental advocate currently residing in the Pacific Northwest. In his spare time, he enjoys experiencing the outdoors, raising chickens and ducks, and reading about current environmental issues. Despite slight colorblindness, his favorite color is green.