Beneficial Species
Composting
Fertilize & Mulch
Garden Plans
Garden Pests
Lawn Management
Pollination
Quick Tips
Soil Management Specialty Gardens

Gardening With Compost Tea

  What is compost tea?

Compost tea home brewer.
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.

  Types of Compost Teas

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 dominated environment.

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.

  Bacterial-Dominated Compost Tea

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 sugar.

  Fungal-Dominated Compost Tea

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

  Setting Up a Home Brewer.

 A 5 gallon bucket with lid
 Compost
 Compost bag
 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)

  Instructions

 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 comparison results.
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!

  Tips To Improve Results

Applying compost tea with sprinking can to plants.

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

Further Information

 Introduction to Composting
 6 Ways to Make Great Compost
 How To Choose a Compost Bin
 EPA: Types of Composting & Understanding the Process

Bees flying footer graphic