Compost tea is a liquid concentrate (that should) contain all the beneficial microbes for which compost is famous. These living beneficial microbes, called the “soil foodweb” are the driving force in a healthy functioning soil. The soil foodweb is responsible for creating & maintaining:
1. nutrient cycling - the break down and reuse of raw organic sources of plant nutrition, and their holding capacity in the soil;
2. improved soil structure - through the formation of soil aggregates;
3. increased porosity - resulting in better aeration and water retention;
4. the degradation of soil pollutants and pH buffering;
Inorganic (chemical) fertilizers, pesticides, herbicides, repeated tilling and mechanical compaction can damage these beneficial soil inhabitants and reduce or delete the benefits of a healthy soil foodweb. This breakdown of healthy soil functioning can be the cause of poor plant growth & color, low resistance to garden pests and pathogens and decreased fruit and vegetable production. Without the re-introduction of the beneficial soil foodweb microbes (commonly found in well made compost), garden maintenance can become a dependant cycle of chemical inputs and controls that then pollute surrounding air via drift and water via leaching into ground water, creeks and bay waters.
The Compost Tea made by Alane Weber is specifically called Actively Aerated Compost Tea (AACT) in reference to the careful brewing process that maintains oxygen levels necessary for aerobic functioning. It is made in accordance with the research and instruction of Dr. Elaine Ingham of Soil Foodweb, Inc. AACT is composed of living biology, and is therefore very sensitive to heat, sunlight and oxygen loss, and should be used quickly (within 2 – 4 hours) and protected from heat and sunlight until application. If you detect “bad”, i.e. rotten smells, do not use the tea, as the biology has been damaged.
Tea brewing & compost production are under the direction of Alane Weber, Certified Advisor for the Soil Foodweb, Inc (www.soilfoodweb.com) and is regularly tested for microbial health and diversity. Test results are available upon request.
Applying Compost Tea
In a backyard situation, the logistics of application are not as difficult or as critical as those done on a commercial scale. However, the basic guidelines are the same, whether you are using a 100 gallon skid sprayer or a watering can.
- The tea must cover 70% of the leaf and stem surface, on all sides.
- On sunny days, when applying with an ultra-fine mist sprayer, apply in early morning or late afternoon to avoid UV rays which could damage the organisms; normal droplet size is not affected.
- Don't apply tea when it is raining heavily. A light misting rain is okay, and may assist organisms to attach to leaf surfaces. Twenty minutes after application, the organisms have created a protective layer over themselves and light rain should not affect them.
- The organisms in the tea are susceptible to physical damage if applied through high-pressure equipment at close range to plant or soil surfaces. Low volume sprayers with moderate pressure below 100 psi are best suited for this type of application. Small pump pressure sprayers, backpack sprayers and hand misters are fine as full coverage of leaf surfaces can be achieved without big drops running off the leaf. But again, don't use them at point blank range.
- Tea should be used as Soon As Possible after leaving the aerated environment of the brewer. Tea that is left standing will go anaerobic in as little as 2 hours on a warm day. Smelly anaerobic tea will result in the death of many of the beneficial organisms and can drastically reduced effectiveness of the tea.
- Compost tea can be used straight or diluted up to 1:4 X, however if chloramated city water is used it must be pre-treated for the removal of the chloramine.
For further information, contact Alane O’Rielly Weber,
@ Botanical Arts, e-mail address: