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Earthworm Castings

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9.00 LBS
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Earthworm castings are highly prized as a probiotic form of compost and one of the highest forms of compost for brewing compost tea.  Our worms are fed a controlled diet of composted Alpaca manure from pastured Alpaca. 


The pH of our castings average in the range of 6.5 +/- and are well-balanced in available forms of nitrogen, phosphorus, potassium, calcium, magnesium, iron, trace minerals, as well as humic, fulvic and amino acids.

That sounds good, but where's the proof?

Click here to view the most recent lab analysis of our castings performed by North Carolina Department of Agriculture Agronomics Division.  

  Our worm castings contain large populations of beneficial microorganisms including active bacteria, protozoa, fungi, and nematodes; along with naturally occurring plant growth hormones, and a number of enzymes.  This diverse biological community forms a symbiosis between plant and soil; helping to build humus and soil structure; assisting with water and nutrient retention; and the recycling of valuable nutrients into forms easily used by plants. 

  Think of it this way, digestive health is the key to the proper absorption of nutrients from our diet.  Much like within our digestive tract, it is a diversity of key organisms within the soil that aides in the digestion or decomposition of organic matter.  Good compost can be considered probiotics for your soil and helps in building a productive and healthy soil ecosystem.   Compost extracts and actively aerated compost teas can improve the digestive health of your soils by inoculating them with billions of beneficial microbes.

Why Compost Tea?

"The point of applying compost tea is to return the biology that should be present, to grow the desired plants with as little effort as possible.  There can be no question that presence of beneficial organisms improves plant growth" -Dr. Elaine Ingham et al, 1985, USDA Soil Biology Primer, 1995.

How do you know that your castings are a good compost for brewing compost tea?

  We have tested our formula several times over with a certified Soil FoodWeb laboratory to ensure we have a diverse living compost that is effective when brewed into compost tea.  You can view a Biological Assessment of our Earthworm Castings here...

Worm castings have excellent bacterial diversity especially when made into compost tea, but how do I balance or enhance the fungal content of worm castings?

  Pre-treating compost to balance or increase fungal biomass; For 5-gallon brewers: * = Optional Ingredients

  • Place 2 – 4 cups of our Earthworm Castings into a plastic container
  • Apply ¼ cup of organic oat flour or finely ground oatmeal across the compost and turn-under
  • Mix the following ingredients with ¼ cup of water
    • 1 tbsp. Soluble Kelp
    • *1 tbsp. Humic Acids
    • *1 tbsp. Fish Hydrolysate
    • *1 tbsp. Soft Rock Phosphate
    • *1 tsp Azomite
  • Apply the mixture evenly to the surface of the compost (should be moist but not saturated)
  • Cover with a loose fitting lid or moist cardboard and store in a cool dark place for 3 – 7 days

  Pre-activation times can vary based upon the presence of active fungi, dormant spores, moisture and temperature. Under the right conditions you should see a white fuzz (fungi mycelium) begin to cover the surface of the compost within 3 – 7 days.  This is an indicator of active fungi and will tell you that your compost is now ready for brewing into tea. Use this pre-treated compost in your Garden Tea Brewer.


  Our worm castings are most effective when used as the primary ingredient in compost tea.  In addition our Garden Tea Co. Earthworm Castings work well for amending soils, planting sites and potting mixes. Applications of Garden Tea Co. Organic Earthworm Castings will help to stimulate a renaissance of life within your soil.  Click here for application rates

Our Organic Earthworm Castings are pollinator friendly.


The bee that appears in the photo above was not prompted, paid or otherwise induced to appear in the photo in any way.  The said bee appeared on its own accord and was not harmed in the production of this photo.

Worm Castings have been recognized to:

  • Improve; the germination rate of seeds, root development and the growth rate of plants.
  • Increase the biological diversity and microbial activity within soil, thus improving soil structure and nutrient cycling.
  • Suppress plant related disease outbreaks and increase the ability to fight insect infestations.
  • Accelerate composting systems and the decomposition of organic matter.

Our Earthworm Castings are packaged by volume and weight

  • 3.5 quart bag (4.5 lbs.)
  • 7 quart bag (9 lbs.)



Satisfaction Guaranteed

6 Reviews Hide Reviews Show Reviews

  • 5
    Looks awesome

    Posted by Carrie on 2nd Dec 2018

    The poof will take time, but these look to be beautiful worm castings. Just getting some seeds and seedlings going for winter greens so if for some reason my opinion changes I will update here. Think I’ve found my new number one choice for castings.

  • 5
    Second time ordered

    Posted by Ryan Williamson on 9th Jul 2018

    Really top quality product from a great company. I can’t recommend Garden Tea Company enough.

  • 5
    Excellent Products - Excellent Company

    Posted by Portia on 18th Jun 2015

    I originally purchased the compost tea brewing kit and had a question. I emailed on a Sunday afternoon (not expecting a response until the following day), but received an immediate response that was informative, polite & professional. Delivery was fast and the quality of products exceeded my expectations. Very impressive! Thanks