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Compost Tea

Welcome to Book of the Week – a weekly feature of an Acres U.S.A. published title offering you a glimpse between the pages! Get the Book of the Week email newsletter delivered directly to your inbox! This week’s Book of the Week feature is Lessons in Nature, by Malcolm Beck.

Nature designed life to reproduce. So Nature designed death to make room for the new life. Then Nature designed decay so the dead bodies could be recycled to nourish the new life. Composting is man’s way of assisting with the decay/recycling process. Through compost, the life cycle is completed. The compost pile is the factory, living quarters and cafeteria for the decomposing workforce of microbes. The fact that compost was at one time a living entity makes it Nature’s finest mulch, soil conditioner and fertilizer.


Over the centuries gardeners and small farmers learned to improve the health and productivity of the soil with the use of compost. But the large farmer and rancher found compost in short supply or considered the labor, equipment and energy needed to spread compost not feasible. However, these large operators didn’t always consult with Nature.

In her wisdom, Nature doesn’t move compost around. She makes compost on the spot where the living entity (whether it is leaf or animal) lies down to die. As the dead things begin to pile up on the soil they create a mulching effect. The mulch creates a favorable environment for microbes. In this environment the decomposing microbes crowd out the harmful microbes while they eat the dead stuff to keep it from overaccumulating on the soil.

When a plant or animal dies, even though it may be consumed higher in the food chain, the decomposing microbes will eventually eat and disassemble it down to the smallest particle. These particles contain the energy and minerals of the once living. The energy and minerals can now blend with the falling rain and create a tea. As the tea soaks into the ground the nutrients are filtered from the water and held in the root zone. From there the plants collect the life supporting forces of mineral and energy, and place them back into the cycle.

Compost pile from which compost tea leached after a 10-inch heavy rain.

When spraying compost tea you don’t get the benefits of the mulch. However, the plants get the health and growth benefits of live, beneficial microbes and nutrients being placed on the leaf surface. The big farmer can create mulch with no-till practices and cover crops. The big rancher can use good grazing techniques, which leaves a cover of living and dead forage that hold the urine and manure deposited to create mulch.

Compost tea machines can be designed that pry microbes loose, without harming them, from the solids they like to cling to. This tea contains a much higher percentage of the good little creatures that help control diseases than tea leached from compost would contain. As little as five gallons of tea per acre (diluted in enough water to get good coverage, sprayed in the evening, over growing crops) has shown miraculous results in improving production and controlling diseases and insects. It has beneficial effects on the leaf surface as well as on and in the soil. At five gallons per acre the benefits and low cost of using compost tea make it very feasible on any size farm or ranch.

To make good tea always use a well-composted blend of approximately 70 percent carbon (wood waste) material and 30 percent nitrogen-rich (animal) material. These percents don’t have to be exact. (Note: the dark stuff, leachate, that drains out of manure piles or unfinished compost is not suitable for spraying on plants.) For a more balanced fungi/bacteria content in the tea, keep it cool (70 to 72 F) while making it. Bacteria seem to dominate when tea is made in warmer temperatures. There is a lot of good compost being made commercially today, but the science of making and using tea for best results is still in its infancy. There is no need to wait for perfection, however. Amateurs everywhere are reporting surprising results.

Making Tea a Simple Way

There are many tea-extracting machines on the market; most are good and some are better. Most are designed with a sack to contain compost or worm castings that is suspended in water and has air bubbled through it for several hours. Some are designed to agitate the compost bag. Nutrient, usually molasses, is added to the water at the rate of an ounce per gallon to feed the microbes.

I have made tea by using a barrel, with a bottom spigot, full of my best compost. Then adding chlorine-free water to the barrel to fill all the air space. I had the barrel setting up high enough to place a bucket under the spigot. After a few hours I would draw off a couple of buckets full of tea and put it back into the top. After an hour or two I would do it again. This process aerated and agitated it some. I would let it set a few more hours then draw all the liquid out for use. This needs to be used within a day or two.

I would dilute it to look like weak iced tea for use in a sprinkle can or pump up sprayer, or I would put it directly through my irrigation system, which would then take care of dilution. I just made sure I got at least five gallons of tea over each acre. I never had to strain this tea. Somehow it filtered itself at the spigot by the time a few buckets were drawn off. I would use the compost in the barrel at least two times. Draining all the liquid from the barrel caused air to be sucked into the compost, which gave it some oxygen. I would let this set a few hours. Then I would fill the empty spaces with water again that had one ounce of molasses per gallon added to it. Adding worm castings to the compost barrel at this time would be excellent. When reusing the compost you can double the time between the draining off and pouring back and than draining it all for use. After the second round of tea making I would use the compost as a mulch or in potting soil.

About the Author:

Malcolm Beck was a lifelong organic farmer and the founder of Gar­den-Ville, a composting/recycling business and retail horticultural supply house. He spoke widely throughout the country, but was particularly well known in south-central Texas. His Garden-Ville operation has grown from a composting pile on his family farm to a multi-million-yard operation in a few years. His compost, fertilizers, bedding mixes, and soils supply leading landscapers throughout Texas. He authored and co-authored many books on organic gardening, including The Secret Life of Compost.