Brewing Compost Tea for Spectacular Gardens

In its simplest form, compost tea is liquid runoff and condensation that is captured from drainage containers under various compost bens and tumblers. Compost tea is also actively “brewed” by steeping healthy compost in water. Using compost tea is a great way to feed plants with soluble nutrients that will impact them more quickly than compost mixed into the soil. Good compost tea also helps to inoculate beneficial microorganisms into the soil and on plant surfaces through foliar feeding.

Making Compost Tea
For making pure compost tea only two ingredients are needed; compost and pure water. It is very important to start with fully finished, high quality compost to make compost tea. Because a relatively small amount of compost is used for making tea in comparison to the amount used when compost is worked directly into the soil, many gardeners would do well to purchase compost that is known to be of the highest quality for use in making their compost tea. The need for pure water for brewing compost tea cannot be overemphasized. Use filtered water that has been de-chlorinated and pH adjusted to 6.5.

In addition to the raw ingredients of quality compost and pure water, a suitable brewing container and “tea bag” will be needed. For most small applications a five gallon bucket with a cover works well for the brewing container and nylon stockings make fine tea bags. The nylon stockings allow only soluble components to enter the tea making it appropriate for spray applications. Compost tea is often produced without aeration or recirculation, but because of the marked benefits of aeration, and the fact that a small air pump can be purchased for less than $10 it is best to provide aeration to the brewing container. Air pumps, tubing and air defusing stones can be purchased at hydroponics or fish stores.

To set up the brewing bucket, attach an air defusing stone to air tubing and place it in the bottom of a five gallon bucket with a rock on top of the air stone to keep it submerged. Fill the bucket to within three inches from the top with filtered water that has been pH adjusted to 6.5. If distilled water is used, it will already be the proper pH and de-chlorinated. If the water contains chlorine, allow it to sit overnight with aeration before adding compost. Next, place a hand full or two of gravel or small rocks into a nylon stocking for weight and then add approximately one pound of quality finished compost. Tie the stocking securely with a string and suspend it in the bucket. Place a loose fitting lid on the bucket to control evaporation and keep foreign matter from getting into the brew.

There is no consistent time for brewing compost tea as it can vary, depending on the method, brewing equipment and environmental conditions. With some high tech commercial compost tea brewing systems, it can be as little as two days. With passive bucket systems it can take as long as three weeks. The longer the compost remains suspended in the water, the greater the amount of soluble materials that will be extracted from the compost. These include both living organisms and the nutrients that will feed them. Compost tea that is well-aerated will require a shorter brewing time than tea made without adequate agitation, so two weeks should be sufficient with this system. Environmental conditions can affect the brewing time and quality of the compost tea. Mild conditions that are neither too hot nor too cold are best. In the summer the brewing container should be placed in the shade. In very cold climates, tea may need to be brewed in the garage during the winter.

After two weeks of brewing the tea is ready for use in the garden. The tea is concentrated and should be used in a 1/10 ratio with water. For best results, use the tea both as a soil based application and in a spray bottle for foliar feeding. Once a compost tea batch is started it is best to allow some of the microbial rich tea to remain in the brew pot for each successive batch.

Variations
Additionally, tea may be brewed using fully composted steer manure or worm castings or even a combination of fish and seaweed. For further study, check into the practice of adding various compounds to compost tea either during the brewing process or just prior to application.

Serious Compost Tea Brewing
Once most gardeners experience the great results that are possible from using quality compost tea in the garden they generally graduate to professionally designed brewing systems. The good news is that these systems can be had for as little as $99 and are available for batches from five gallons to 9,000 gallons per day. The following are good resources for those interested in buying a quality compost tea brewing system.

Keep It Simple - http://www.simplici-tea.com/
North Country Organics - http://www.norganics.com/
VermiCo - http://www.vermico.com/
Acme Worm Farm - http://www.acmewormfarm.com/
Sustainable Agricultural Technologies - http://www.composttea.com/
Bob’s Brewers http://www.net-time.com/bobsbrew/