Get Familiar with Earthworm Castings & Compost Tea


James Gist, CFO at Brick Ends Farm in Hamilton, Massachusetts took the time to explain how compost tea is made from earthworm castings and why it is beneficial for lawns, trees and gardens.

Earthworm Castings

“In essence, you have an “incubator” and in the incubator are thousands of earthworms. We put our own Brick Ends Farm compost into that to feed the worms and the worms produce castings. You harvest the castings through a process of removing them from a giant sheet which is hooked on to the bottom of the incubator.

Compost Tea or Earthworm Casting Tea

You then take those castings and you create what is commonly called compost tea or earthworm casting tea which is a higher value product. We use a machine to change the castings from a solid to a liquid then we can add a number of different additives from sugar to kelp depending on the nature of the treatment, i.e.: lawn or trees or root systems. The bacteria biology is activated by adding different additives. When you combine the additives into the extract that is the definition of the tea. Just like a regular cup of tea, you want to add a little sugar to it.

Large Scale Tea Production

We can make 2000 gallons of compost tea in a 2-3 hour period. We have a large scale operation so what we like to do is educate people on the applications of compost tea. Not only for Arborjet service provider, Mayer Tree Service and other arborists but more importantly for plants, vegetation, grass, you name it! A lot golf courses even use it in their sprinkler systems.

Tea vs Fertilizer

You can use organic compost tea as a fertilizer. Does it replace all fertilization? No, but you can get pretty close if you have included the right additives. This is a more environmentally way to fertilize. This is unlike regular fertilizer which requires rain or watering to create the activation process. If you go fertilize your backyard, you’re going to hope that it starts raining in the next couple of days because you don’t want to burn the yard but you don’t want it to rain too much because then it washes all of the fertilizer away. However, if you use a pre-mixed liquid fertilizer, you would be applying biology to the chemistry that is already in your soil.

Compost Tea & Droughts

In staving off drought it’s all in how you set up the soil. The biology will help a vegetable garden more than just planting in the dirt, as compost has 60% more hydroscopic properties than soil, so it holds water. Adding compost tea during a drought will add more biology to the soil. One of the building blocks of tea is water, so if you watered down the tea and sprayed it on a lawn you would see some beneficial growth factor because you are applying biology-chemistry to the plant. When the biology and chemistry mix, we have the growth factor, which encourages growth and deeper roots systems. Because of the increase in root depth, no matter the drought situation, your grass is going to stay greener because it is getting the water and the moisture it needs. So, even with a little bit of water or rain, your lawn will look much better because your roots systems will be healthier and more developed.”