Gardening With Compost Tea
Compost Tea Home Brewer
Compost tea is an aerobic water solution that has extracted the microbe population from compost along with the
nutrients. In simple terms, it is a concentrated liquid created by a process to increase the numbers of beneficial
organisms as an organic approach to plant and soil care.
As you might guess, there are many other alternatives in creating compost tea and the recipes vary in fostering
the differential growth of bacterial and fungi.
The two most common types of compost teas are (1) bacterial-dominated tea and (2) fungal-dominated tea. So
what is the difference between bacterial and fungal compost tea?
If you consider what happens in nature, an acre of land that is left fallow will begin to regenerate using annual plants
(weeds) and then gradually progress into a more perennial species (grasses and vegetables). This is a bacterial soil
Eventually this land will turn into a forest (perennial hardwoods) whereupon the fungi in the soil will become more dominant
that the bacteria.
It is important to understand this distinction as it determines the type of compost tea that should be used for a particular
plant. Ideally you try to match the type of compost tea you are using for the type of plant you are growing.
The bacterial dominated compost tea is best suited for annual plants including flowers, vegetables and grasses.
Most lawns, somewhat pasture-like, will be bacterial as they are mowed and constantly recycle green matter.
Bacterial Dominated: Basic Tea Recipe
1.5 pounds of bacterial-dominated
compost (vermicastings works well)
2 ounces of cane sugar
1 ounce of soluble kelp
Bacteria love simple sugars, so feel free to add in a teaspoon of maple syrup, or even white
The fungal-dominated compost tea is best suited for perennial plants including woody plants, shrubs and trees.
Fungi don’t like to be disturbed. Turning the soil destroys the intricate network of fungi mycelium
that makes the whole system function. Turning or roto-tilling damages the strands and exposes the
light-sensitive growth to the sun which kills the mycelium. A good fungal soil will reveal itself by sprouting mushrooms
when a rain is followed by a dry spell.
Fungal Dominated: Basic Tea Recipe
2 pounds of fungal-dominated compost
(see tips at bottom of page)
2 ounces humic acids
2 teaspoons of yucca extract
1 ounce of liquid kelp
2 tablespoons of ground oatmeal
A 5 gallon bucket with lid
An aquarium pump
A length of air hose long enough to go from the pump to the air stone
An air stone for an aquarium
Water (let stand for 24 hours if chlorinated)
Pretreat your compost to increase its inoculant
and fungal power. Take your compost
inoculant and add some humic acid or fish emulsion to it. Put it into a shallow tray and mix it
up well. Then let it sit for two to three days. This encourages fresh microorganism growth in
the tea. You can treat this as an optional step or you can see it as a way to increase the
effectiveness of your brew.
Compost Tea Results Comparison
Fill a bucket with non - chlorinated water. The water temperature is ideally between 55-80oF.
If using tap water, leave it sitting and uncovered for 24 hours to off-gas any chlorine, or add
humic acid to it to deal with chloramine.
Put the pump air stone (from an aquarium store)
in the bottom of the bucket, attach the air
pump and let it start to bubble. Make sure there is enough oxygen and agitation moving
through your liquid. Remember, you are looking for more of a churning or rolling boil, not
simply fine bubbles.
Put compost in the panty hose stocking or mesh
bag, tie off the end and suspend it in the water.
If you want to increase the
diversity of your compost tea, we suggest adding a cup or two of
garden soil. Better yet, if your compost tea recipe calls for fungal compost, include a cup or
two of soil from a nearby forest. By adding these additional soils, you're ensuring your tea is
inoculated with a wide range of soil microbes. These soils are like a biological catalyst, or
compost tea activator.
Add the food.
Let the whole brew bubble for 12 hours and for no longer than 18 hours. After 18 hours, if the
tea received insufficient oxygen or too much food, anaerobic organisms will overcome the
beneficial aerobic organisms. It will be obvious if the tea went anaerobic, because it will stink!
1. If you want to increase the diversity of your compost tea, we suggest
adding a cup or two of garden soil. Better yet, if your compost tea recipe calls for fungal compost,
include a cup or two of soil from a nearby forest.
By adding these additional soils, you're ensuring your tea is inoculated with a wide range of soil microbes. These
soils are like a biological catalyst, or compost tea activator.
2. Don't accidentally filter out your fungi (and nematodes) when straining your tea.
When filtering your tea, be sure your screen is as close to 400 micrometers as possible. Paint
strainers, from your llocal hardware store, work quite well for this function.
Avoid using socks or pillowcases, since their fibers are too tight.
3. When you want to ensure that you have fungi in your tea, brew it and then add
spores of mycorrhizal fungi. Mycorrhizal fungi act as a wonderful inoculum to any fungal compost tea recipe.
These fungi naturally form beneficial relationships with approximately 95% of all plant species. They aid in nutrient
transfer to plants, and help to create better soil conditions
4. There are commercial setups for brewing compost tea that make it easier to get
started including pre-packaged compost and food for the bacteria and fungi
Introduction to Composting
6 Ways to Make Great Compost
How To Choose a Compost Bin
EPA: Types of Composting & Understanding the Process