Actively Aerated Compost Tea

Author Ellen Vande Visse

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Teas #3 Actively Aerated Compost Tea to Nourish Your Plants

All the soil minerals in the world won’t make your plants grow unless you have the soil biology to deliver these nutrients. It is the soil microorganisms—namely bacteria, fungi, protozoans, and nematodes— who transform soil minerals into forms plants can use. This is how nature works, and the more diversity and higher numbers of microbes, the healthier the soil and plants will be.

Like compost, compost tea contains this plethora of microscopic organisms that we call soil biology or the soil food web. There is compost tea and actively aerated compost tea (AACT). What’s the difference?

Compost leachate tea. You could soak some compost solids in water. It would steep. You’ll get a brown-stained liquid that contains some soluble nutrients and a few microbes. You could declare it to be compost tea. This is actually called a compost leachate tea.

In comparison, actively aerated compost tea is a culturing process. One starts with a specific amount of compost solids in a measured amount of de-chlorinated water. Then one adds microbe foods in prescribed amounts, and vigorously oxygenates the mixture for 24 hours.

The result? Super-multiplication! The brewing process breeds millions more times the beneficial microbes, compared to the original compost, compost leachate tea, or even worm juice or manure tea. In short, you have a tea that teems with vastly larger numbers and greater diversity of essential soil microorganisms.

When you apply this actively aerated compost tea, you are providing a concentrate of soil biology—tiny workers to effectively deliver nutrients to your plants, and boost their vitality, resiliency, and disease resistance.

What makes a high-quality compost tea?

  • Start with high-diversity aerobic compost or combination of composts
  • Provide the proper ratios of water, compost, and microbe foods
  • Aerate vigorously, usually 24 hours
  • Lab-test the results to assure the recipe delivers consistent results of desired soil biology


Can I use AACT alone as a fertilizer?
While actively aerated compost tea contains some nutrients, it is not really considered a fertilizer. Its strength is as a microbe inoculant. The microbes are the “delivery specialists” who release those locked- up soil minerals into forms your plants can use. In your garden, combine your tea application with an application of an organic fertilizer such as blood meal, fish meal, alfalfa meal, soybean meal, fishbone meal, cottonseed meal, or fish emulsion. This gives your soil 1) the workers and 2) their lunch boxes to sustain their services.

Other benefits? I’m excited about actively aerated compost tea (AACT) because it:

  • Is a liquid concentrate, so a little does a lot. Four gallons of compost thinly covers 150 sq. feet. Four gallons of AACT effectively treats an acre.
  • Is an effective way to restore degraded lawns, pastures, hayfields, ball fields, and croplands.
  • Is a liquid so it can be a foliar spray to prevent diseases (e.g. gray mold, powdery mildew, black spot, and apple scab).
  • Brings sick annuals and perennials back to health.
  • Stimulates house plants bloom that did not before.
  • Re-vitalizes dead spots and doggie spots in lawns. Just sprinkle grass seed, soil, and AACT.
  • Eases transplant shock.
  • Builds water retention, drought-resistance, soil structure, and enhances fungal networks like compost does.
  • Stops barn & coop odors—spray with compost tea and Ta Da! Odors gone.
  • Activates your compost pile—sprinkle compost tea as you layer a new pile, or as you stir an existing pile.


Where to get some?
You can purchase my high-quality AACT brew from Good Earth Garden School near Palmer during May and June. Please see dates and ordering details in the Good Earth Garden School website Store. Gallons are $5 each.