Compost Tea Info

Tea for Plants / Tea for the Planet

nourish your earth, plant and people


What is Compost Tea?

Much like herbal teas, compost tea can be simply described as a water extraction of compost; compost soaked in water to extract the many beneficial nutrients and more importantly the diverse biology present in good quality compost.  Once suspended into a liquid solution, the beneficial organisms in the liquid compost can easily be applied to soil, turf, leaf surfaces, compost heaps, ponds or other natural systems.

Why Compost Tea?

  "The point of applying compost tea is to return the biology that should be present, to grow the desired plants with as little effort as possible.  There can be no question that presence of beneficial organisms improves plant growth" -Dr. Elaine Ingham et al, 1985, USDA Soil Biology Primer, 1995.  Dr. Elaine Ingham has been a leading researcher and authority on the subject of compost tea, working to identify target organisms necessary for healthy agricultural and ecological systems. 

  Home brewed compost teas are very affordable and serve as a living fertilizer, working extremely well in building a productive and healthy soil ecosystem.   In addition, compost teas provide a healthy alternative to toxic chemical fertilizers and can be used on lawns, vegetable gardens, annuals, perennials, houseplants, shrubs, trees, orchards, forests, and vineyards with no threat to pets, livestock or humans.

What does Compost Tea Do?

  Compost tea and compost extracts act as a probiotic for your soil.  Digestive health is essential for the proper conversion and absorption of nutrients from our diet.  Much like within our digestive tract, it is a diversity of key organisms within the soil that aid in the digestion or decomposition of organic matter and the conversion of nutrients into forms readily available to plants.  The collective biology at work in soil is responsible for building humus and soil structure, assisting with water and nutrient retention, as well as the recycling and mining of nutrients and minerals.  Compost extracts and actively aerated compost teas can improve the digestive health of your soils by inoculating them with billions of beneficial microbes.  Specific organisms present in compost have been identified to possess disease suppression capabilities and the capacity to form a protective barrier from disease and pests throughout a plants root and leaf zones outcompeting pathogens and parasitic organisms for food resources.  Building a diverse soil ecosystem teeming with life will help to improve the health and productivity of your farm and gardens.

  "The problem in agriculture has not been a lack of nutrients, but a lack of the proper biology to make those nutrients available to plants." -Dr. Elaine Ingham, Soil Foodweb, Inc. 

What is the difference between compost tea, compost extract, and actively aerated compost teas (AACT)?

  The term compost tea is used, broadly at times, to describe a variety of liquid compost and mineral solutions.  Ideally, compost teas should be a living liquid compost possessing a full-diversity of the biology present in compost.   

  Compost extract can be made very quickly when there is not enough time to brew aerated compost teas.  Compost extracts can be used as a soil drench, root dip when transplanting or to inoculate potting and planting mixtures.  Stir compost in water for a minute or two and whoala!  Compost extracts will contain some humic acid as well as a similar concentration of the microbes found in the starter compost.  Humic acids are great for purifying a municipal water source prior to making tea.

  Actively Aerated Compost Tea (AACT) is a water extraction of compost using high volumes of oxygen, thus maintaining a highly aerobic environment and a more precise cultivation and extraction of the beneficial organisms present in the compost.  Aerated compost teas can be fed specific ingredients to cultivate select microbial life present in the mature compost.  The increased oxygen levels and select foods added to aerated compost tea act as a catalyst feeding the diversity of organisms into an accelerated growth.  Actively aerated compost tea can be applied as either a soil drench or as a foliage spray.

For further reading on brewing and working with compost tea we recommend the following books:

Here is a direct link to recommended books from Soil Foodweb Inc...

The Soil Biology Primer - by: Published by the U.S. Department of Agriculture; contributing writers, Dr. Elaine R. Ingham of Oregon State University, Dr. Andrew R. Moldenke of Oregon State University and Dr. Clive A. Edwards of Ohio State University

The Compost Tea Brewing Manual - by: Dr. Elaine Ingham

Teaming with Microbes - by: Jeff Lowenfels & Wayne Lewis

Secrets of the Soil - by: Peter Tompkins & Christopher Bird

The Rodale Book Of Composting; Rodale Press


Compost Tea Research

The links below will take you to studies and stories on the effect of compost teas on a variety of plant types.  

- "The Soil Biology Primer" from the USDA Natural Resource Conservation Service 


"Compost tea research enters its Second Year"
"Study aims to shed light on current debates over the safety and efficacy of compost tea as an organic material
" from - The Rodale Institute New Farm Research Report


Organic Landscaping | Landscape Services | Facilities Maintenance Operations | University Operations Services | Harvard University


- Harvard Yard Soils Restoration Project Summary Report Februrary 2009 from the Harvard Facilities Maintenance Operations


- "Organic brew puts green back into Yard" from the Harvard University Gazette


"Compost Tea and Milk to Suppress Powdery Mildew (Podosphaera xanthii) on Pumpkins" form the University of Connecticut 


- "Compost Tea Study" from Yale University Office of Sustainability 


by Vern Grubinger 
Vegetable and Berry Specialist 
University of Vermont Extension


 "The Myth of Compost Tea, Episode I: compost tea is an effective alternative to traditional pesticides" by: Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University


- "The Myth of Compost Tea, Episode III: Aerobically-brewed compost tea suppresses disease" by: Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University