Compost Tea

(Question)

Is compost tea useful? I don’t have space to make my own compost, but can get a bit of compost from a friend to make tea. Worth it? Recommended recipe and application? I see multiple variations on the web. Want to do a simple one, not the version with fish tank motors, etc.

(Answer)

Thank you very much for your question.  I am delighted that you would like to improve your soil naturally – natural soil amendments are not only the best option for improving the fertility and health of your soil and plants but also ecologically friendly.  However, the Toronto Master Gardeners cannot recommend the use of compost tea.  There is little to no scientific evidence supporting the use of compost tea – I would recommend this very thorough article written by Linda Chalker-Scott.  There may also be risks to the use of compost tea – you do not know which microbes you are encouraging to grow, and harmful pathogens such as E. coli or salmonella could be present.  I would therefore particularly discourage its use on edible plants.

Instead of the time and work necessary to brew compost tea, why not add the compost directly to your soil? In addition to your friend’s compost, the City of Toronto also offers free compost pickup on community environment days.  If you don’t have the space to make your own compost, vermicomposting, or composting with the help of worms, can be done in a very small space such as a bin under the kitchen sink, and worm castings are an excellent soil amendment.  Here is a helpful article on vermicomposting from the Canadian Wildlife Federation: https://cwf-fcf.org/en/explore/gardening-for-wildlife/how/earth/compost-and-other-natural-fertilizers/vermicomposting.html

Happy gardening!

June 1, 2022