How to Make Your Own Compost Tea

April 21, 2016 Updated: April 21, 2016

By Ali Lawrence, Organic Lifestyle Magazine

If you’re still using plain old compost, you’re living in the past. These days gardeners are raving about the wonders of compost tea. Compost tea is liquid gold for plants; it fertilizes and suppresses diseases. This liquid fertilizer is relatively cheap and easy to make, and it provides your plants with instant nutrients to support their growth, improve their nutritional value, and even improve the flavor of your crops.

What You Need

Making your own compost tea requires a few key ingredients to get started. You shouldn’t try to make compost tea without some kind of aeration equipment; the organisms in the tea will quickly deplete the oxygen and your tea will start to stink.

  • A 5-gallon bucket or larger, depending on how much compost tea you need; 5 gallons is the smallest amount I recommend makingAn aquarium pump
  • Several feet of tubing
  • Something to stir the mixture with
  • Something to strain the tea with, like a nylon stocking or old pillowcase

How to Make Homemade Compost Tea

Once you have everything you need, it’s time to set up your equipment and get brewing.

You can formulate your tea specifically for whatever project you’re currently doing. For instance, molasses boosts bacteria which is beneficial to grasses, but protein like fish oil boosts fungal activity which is more beneficial to large shrubbery or trees. If you’ve never made compost tea before, you’re about to have some very happy plants.

  1. Set up your pump: Attach the tubing to the aquarium pump. Make sure the tube is securely attached and no air is escaping. Fix tubing to the side of your container with clamps, or bury the end of the tubing under your compost to keep it in place. Find a location for your bucket that is warm but not directly in the sun. Direct sunlight can promote algae growth and throw off the balance of nutrients in your compost.
  2. Mix together your ingredients: Put your compost in the container; you want to have a good balance of carbon-based and nitrogen-based compost. High carbon materials are things like: wood, ashes, bark, shredded newspaper and sawdust. High nitrogen materials are: coffee grounds, grass clippings, manure and seaweed. Loosely fill your bucket with compost about three-quarters of the way, making sure the mixture isn’t packed too tightly to stir. Now you want to add water to your mix. Rainwater is preferable since it lacks the chemicals that tap water may contain. Fill the bucket with water, leaving enough room at the top so you can stir without spilling or splashing.
  3. Start your pump: Turn your pump on and wait to see if you need to adjust it. After a few minutes you should see bubbles in your mixture; it should look like it’s boiling. If your pump isn’t producing enough air, adjust the pump up or down as needed.
  4. Add some food for the microorganisms: Once your pump is running smoothly and aerating as it should, add in one ounce of organic unsulfured molasses and stir your mixture.
  5. Let the tea steep: Vigorously stir your mixture a few times a day to release more organisms and increase aeration. Let your tea brew for about three days, turn the pump off and remove the equipment. Unclamp your tubing from the side of the bucket, disconnect tubing from the pump and unplug the pump.
  6. Strain your tea: Allow the tea to settle for a few moments so the largest pieces of matter fall to the bottom, making the mixture easier to strain. Strain your liquid into another bucket or directly into your sprayer. The strained material can go back into your compost pile, but should not be used to make tea again since brewing has removed a lot of nutrients from the organic material. If you want to make a new batch, start with fresh compost.
  7. Use your tea: Now that your tea is ready you’ll want to use it as soon as possible. Your tea needs to be diluted with water to protect your plants. The final liquid mixture is extremely concentrated and may burn your plants, especially if your compost was nitrogen-rich. Dilute your mixture about one part compost tea to 10 parts water.Once again, for best results try to use rainwater or water that has been dechlorinated. In early morning or evening when there’s less chance of leaf burn, apply the liquid to the leaves and roots of your plants in the garden. Safer Brand, an organic gardening company, suggests using compost tea on your lawn as well. “When establishing a new lawn or restoring a sparse area, use compost tea to inoculate the soil with microbes that break down nutrients for grass roots.”
(Denis Pogostin/iStock)
(Denis Pogostin/iStock)

If normal compost just isn’t cutting it for your plants, this nutrient-rich liquid may be exactly what they need. Not only are you putting that compost to good use, you’re growing healthy and nutritious plants – while also enriching the soil in your garden.