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How to Plant, Grow, and Harvest Real Tea

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Compost Tea: Brewing a Nutritious Drink for the Garden

Applying compost tea to the soil or to leaves is a good way to get aerobic bacteria to garden plants. This can have the beneficial effect of reducing the possibility of plant diseases and at the same time feeding the plant with necessary food. The idea is to extract nutrients and micro-organisms from compost by a soaking, brewing, or "steeping" process.

Making compost tea is not an easy process. The brewer must be careful to avoid growing anaerobic micro-organisms which will actually harm plants. E. coli can also be a danger if aerobic bacteria are not properly fostered1. To make compost tea, an actual compost tea brewing kit is recommended.

However, compost tea can be made using readily available materials. To accomplish this, begin with compost from a pile that has reached at least 135°F (57°C) for several days. If a sprayer is to be used to distribute the tea, a fine meshed compost "tea bag" such as an old nylon stocking may be used. For more robust tea that is to be poured on the soil a rougher bag may be used such as old nylon screen. The bag can then be suspended in a five-gallon bucket half-filled with water. It is best if this is untreated water, such as rain water. Tap water is often loaded with chemicals such as chlorine that will kill many of the beneficial micro-organisms.

Because the micro-organisms within the tea are constantly using up the oxygen, the tea must be kept aerated; otherwise unhealthful anaerobic bacteria will take over. An aquarium aerator may be used. Connect it to a tri-gate and feed three or more tubes to the bottom of the bucket to release air into the water. Now, the micro-organisms can be fed with an ounce of molasses stirred into the mixture. Stir again every eight hours or so. The tea is ready in about 24 hours, but can be kept brewing for up to 72 hours; when, if it is not immediately used, more molasses should be added.2 The ideal temperature for brewing compost tea is about 70°F (21°C), but will still work in a range of about 55°F to 95°F (13°C to 35°C).

When the tea is ready, remove the bag and return the contents to the compost bin. If using a sprayer to apply the compost tea, use a filter (another stocking is good) to remove sediment and any floating debris. The tea should be used within an hour. The lack of oxygen - once the aerator is turned off - will soon begin to kill the beneficial micro-organisms, and encourage the anaerobic ones.

The main reason to make compost tea is to be able to spray it directly on plants. This can be done up to every two weeks. In which case it should be sprayed on both the top and the underside of the plant leaves. Remember, the smell of the tea should not be unpleasant. If there are bad odors within the tea, this is a sign that the unhealthy anaerobic bacteria has gotten the upper hand. In this case do NOT apply it to the plants as anaerobic bacteria creates alcohol that can damage plant cells. If the tea has not gotten too bad, more aeration and the addition of more molasses may solve the problem.

Compost tea can help solve many disease problems occurring on plants. But of course, it does not solve all problems. For organic gardeners who disdain the application of chemicals, a certain amount of damage due to insects and disease is to be expected. Even so, the organic gardener, using compost tea and other composting methods can expect produce of superior quality and taste, as well as beautiful ornamentals.

Previous Page: How to Make Compost with Worms
Next Page: Troubleshooting the Compost


  1. Soil Food Web on Compost Tea
  2. Perfect Perennials


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