Compost Tea – Step by Step

Table of Contents

Making compost tea is a natural fertilizer for plants that can be applied while watering the garden. It is yet another creative way to reuse garden and kitchen waste, while also saving you time and energy when caring for plants.

What is Compost Tea?

a bucket with aerator and a bag of organic material submerged in water to make compost tea
Compost tea is a tea steeped from compost material that is for plants. The same beneficial microorganisms that thrive in compost are transferred to a liquid that can be applied to the soil, incorporated when the plant is watered, or sprayed on the leaves. It is critical to make the tea with good quality compost. Traditional compost tea ingredients include water, compost, molasses and air.

Making Compost Tea

composite image showing supplies for making compost tea; bucket, organic material, molasses, and cloth sack

Supplies Needed for Making Compost Tea:

  • High-quality compost
  • Five-gallon (20-liter) bucket
  • Burlap bags or food strainer bags (“tea bags”)
  • Dechlorinated water
  • Aquarium-sized pump
  • Aquarium pump tubing
  • Aquarium air stone
  • Molasses

Steps to Making Aerated Compost Tea Recipe

a bucket of compost tea in production using a large bucket and an air tube connected to an aerator
  1. Add two heaping cups (400 grams) of compost to a “tea bag” and tie it off with twine.
  2. Fill up a five-gallon (20-liter) bucket with dechlorinated water, leaving about three inches (eight centimeters) of space at the top.
  3. Place the air stone in the bottom of the bucket and submerge the “tea bag” of compost.
  4. Add one-third cup (113 grams) of liquid molasses.
  5. Turn the pump on to add air to the water and allow it to run for about 36 hours.

Steps to Make Non-Aerated Compost Tea Recipe:

a bucket of compost tea covered with fabric mesh, the tea contains chunks of organic material and is being made without aeration
  1. Fill a five-gallon (20 liters) bucket with dechlorinated water, leaving about three inches (eight centimeters) of space at the top.
  2. Add two heaping cups (400 grams) of compost directly to the water.
  3. Add one-third cup (113 grams) of liquid molasses.
  4. Stir vigorously for two minutes, twice per day, for about seven to ten days.
  5. Filter the mixture through a strainer.

What are the Benefits of Aeration?

close-up of an aerator producing bubbles underwater
Actively aerated compost tea (AACT) increases the microbial activity in good compost, which creates a more actively beneficial finished compost tea. It is also a more hands-off approach, allowing gardeners to “set it and forget it” until it is ready to be used. The only downside to the aerated approach is that it requires an investment in equipment and takes some time to set up.

Compost Tea Feeding Schedule and Application

hand scooping cups of compost tea from large bucket and watering tomato plants with the tea

How to use compost tea:

  • Add about one cup (340 grams) of tea directly to the roots of plants.
  • Pour compost tea into a watering can and water beds or pots as needed.
  • After using up the tea water, cut open “tea bags” and incorporate the contents into the soil at the base of plants or trees.
Compost tea should only be brewed in batches that can be used right away, as it does not store well. It is a gentle, natural fertilizer for plants, so it can be applied as frequently as watering is required. Allow the top layer of soil of potted plants to dry out between waterings to avoid root rot.

Why Compost Tea Instead of Regular Compost?

woman filling a spray bottle and jar with compost tea to use for fertilizing plants
Using compost tea is like applying compost directly, but it is more readily absorbed by the plant’s roots since the nutrients are already in liquid form. Using compost tea rather than straight compost can also be easier for the gardener, and less messy since it can be added to irrigation systems or watering cans. This allows the gardener to do two steps at once.

Is Compost Tea Safe?

a colorful pile of organic waste from kitchen scraps such as orange peels, bananas, and potatoes
Compost tea is safe, provided the original compost is of excellent quality. The air and sugar that is added to the compost will help to feed and multiply the microorganisms that are growing therein but will not differentiate between good organisms and bad organisms. So, the compost must come from a clean source where bad bacteria (such as the bacteria that can live on animal products or other materials that should not be added to compost bins).
Compost tea can save gardeners time and effort when caring for their plants. It can be low-cost and easy to implement to any gardening regimen. Compost tea is a natural fertilizer for plants including vegetables, flowers, and trees. It is also another way that gardeners can make the most out of their households, reuse waste rather than discard it, and be a part of a greener future.
metal watering can sitting next to a wood raised garden bed filled with different herb plants


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