Compost Tea

In my experience, compost tea is one key to tomato growing success. Initially, I learned about compost tea when I attended a seminar taught by Jeff Lowenfels, who is one of the authors of the book, Teaming With Microbes. Then I purchased the Simplici-Tea compost tea kit from Keep It Simple (KIS) Farm in Redmond, Washington and have been brewing my own since 2005 with excellent results. This is a product that is safe and organic, inexpensive, simple to create yourself, easy to apply and it really works.

What is compost tea?

Basically, compost tea is the solution you get when you place some compost (or vermicompost) along with some extra nutrients into a bucket of water equipped with a small pump that bubbles air into the water--like in an aquarium, for a day or two. This is not to be confused with leaving compost in a bucket of water to sit for a couple of days. Without an air pump, the resulting solution would contain mostly bad-smelling anaerobic bacteria that might even be dangerous. The bubbling action of the pump separates the microbes from the compost while keeping them alive and allowing them to multiply, producing billions of beneficial, aerobic microbes in several gallons of water. The resulting mix should not smell bad.

How do you make Compost Tea?

I purchase compost tea bags from KIS Farm and brew them in my KIS Brewer which is a 5-gallon bucket equipped with a pump. Click here for KIS brewing instructions.

This system is inexpensive, easy to use and I believe it’s the only 12-hour brewer currently on the market. The ready-to-use compost tea bags are a prepackaged balance of bacteria and fungi along with the extra nutrients for microbes and plants. Using these takes any guesswork out of the equation since they contain both bacteria and fungi along with other nutrients. The combined solution benefits all of my plants including tomatoes, roses, lawn, trees, shrubs, berries and vegetables. According to Teaming With Microbes,  annual plants prefer the bacteria in the solution where perennials, shrubs and trees prefer the fungi. Since vermicompost (compost from a worm bin) tends to be bacteria-dominant, it would probably make a good tea for tomato plants and other annuals, but you would need to do some research to find a recipe if you plan to create your own compost tea bag. There is more information on building your own tea brewer in the book: Teaming With Microbes.

How do the microbes help in the garden?

The microbes help in the root zone and on plant surfaces.

In the root zone, an influx of beneficial microbes can out-compete bad ones for nutrients and space.

On plant surfaces, microbes can provide protection from attack due to insects or diseases.

Other benefits, according to Keep It Simple, include:

--Helps extend root systems

--Increases water and nutrient retention

--Helps breakdown toxins in soil and on plants

--Enhances taste of fruits and vegetables

Do compost and mulches offer the same benefits?

Compost and mulches contain the same microbes, however it takes a lot longer for them to get to the root zone and they cannot attach to plant surfaces at all. Plus compost tea has been shown to contain four times the number of microbes as compared to compost.

For specific information on working with microbes, building your own brewer, creating compost and more, I highly recommend reading Teaming With Microbes.

For information on the KIS Brewer and tea kits, I recommend visiting the Simplici-Tea website. 


Teaming With Microbes. Jeff Lowenfels and Wayne Lewis. 2006. Timber Press.