California Department of Resources Recycling and Recovery (CalRecycle)

Organic Materials Management

Compost Tea

Soil needs the right biology to grow and sustain healthy plants. If your soil, potting mix, hydroponics medium, or compost lacks healthy organisms or soil Biology, establish the right organisms with compost tea.

What Is Compost Tea, and Why Use It?

The tea is produced by "steeping" healthy compost in water using some method of aeration. Compost tea is brewed from compost and a microbial food source additive, such as molasses, kelp, rock dust, and humic-fulvic acids.

Why brew and spray this tea?

  • To inoculate microbial life into the soil to feed plant foliage.
  • To add soluble nutrients to the foliage or soil in order to feed your plants.

The compost tea brewing technique, an aerobic process, extracts and grows populations of beneficial microorganisms. This is especially important if soil has been subjected to chemical-based pesticides, fumigants, herbicides, and some synthetic fertilizers that kill a wide range of beneficial microorganisms that encourage plant growth. Compost tea improves life in the soil and on plant surfaces.

Compost Tea and Disease Suppression

There have been a large number of testimonials suggesting that compost tea has improved the ability to manage plant diseases. Growers experience indicates that both compost extracts and teas can suppress the incidence and/or severity of foliar and root rot diseases.To learn more about the views, concerns, and discussions on this issue, visit:

Last updated: April 3, 2012
Organic Materials Management http://www.calrecycle.ca.gov/Organics/
Contacts: http://www.calrecycle.ca.gov/Organics/Contacts.htm