Growth in gardening: The Magic of Compost Tea

Compost tea has been shown to increase plant growth, provide nutrients to the plant and soil, help suppress plant disease and provide beneficial organisms. PHOTO COURTESY OF JOE URBACH

Last week in this column I was talking about starting seeds and I briefly touched on compost tea. I promised an article about this magic elixir this week, and while I know I have written about this mixture in the past I wanted to give you an easy, affordable method for making this liquid gold. So let’s jump right into it.

What is so wonderful about compost tea? Well, for starters, it is simply the most amazing stuff around. For one thing, it is everything your plants are wanting and you can make it right at home, – for free mind you – from your own fresh, well-finished compost. Which means no more throwing away money on expensive fertilizers. The only requirement is that the compost you use be well broken-down into minute particles, this is called finished compost. This usually means that the organic materials have decomposed over a period of time so that their appearance is very dark with the texture of course crumbly cornmeal. Oh, and the fragrance is like that of the rich soil one finds in a forest.

Don’t have such compost yet? Well, dig deep down inside your bin, near the bottom. This is where organic material will be most decomposed and fresh. All you need is a good shovelful for a 5-gallon bucket of Compost Tea. If you have never “brewed” your own compost you sure need to give it a try. After all, this stuff is like a fantastic smoothie or a good cup of espresso to your plants.

A fairly new phenomenon to gardening is the deliberate creation of the magic potion that is compost tea. Researchers have determined exacting and scientific ways to brew it. The result has been the creation and promotion of compost tea brewing equipment, available at fine garden centers or on the internet. Some garden centers, in fact, have begun “brewing” the tea in large batches so that customers can draw-off what they need by the gallon. But let’s not get too crazy here, the homeowner is not obligated to use exacting methods to get some very fine tea. All you need is a couple of buckets, a shovelful of fresh finished compost, water and a straining cloth such as cheesecloth or burlap, heck for the first few years I was making compost tea I used an old pillowcase as a straining cloth.

I keep singing the praises of this stuff but I still need to provide a few good reasons to make you own compost tea, don’t I.

Benefits of compost tea:

  • It increases plant growth - It is chock full of nutrients and minerals that give greener leaves, bigger and brighter blooms and increased size and yield of vegetables.
  • It Provides nutrients to plants and soil - The fast-acting nutrients are quickly absorbed by plants through their leaves or the soil. When used as a foliar spray plant surfaces are occupied by beneficial microbes, leaving no room for pathogens to infect the plant. The plant will suffer little or no blight, mold, fungus or wilt.
  • It provides beneficial organisms - The live microbes enhance the soil and the immune system of plants. Growth of beneficial soil bacteria results in healthier, more stress-tolerant plants. The tea’s chelated micronutrients are easy for plants to absorb.
  • It helps to suppress diseases - A healthy balance is created between soil and plant, increasing the ability to ward off pests, diseases, fungus and the like. Its microbial functions include: competes with disease causing microbes, degrades toxic pesticides and other chemicals, produces plant growth hormones, mineralizes a plant’s available nutrients, fixes nitrogen in the plant for optimal use.
  • It replaces toxic garden chemicals - Perhaps the greatest benefit is that compost tea rids your garden of poisons that harm insects, wildlife, plants, soil and humans. It replaces chemical-based fertilizers, pesticides and fungicides. And, it will never burn a plant’s leaves or roots. Finally, you save money.
  • It makes you a “Green Planetary Citizen” - Compost tea is just another way to feel good about respecting the earth in your own yard and garden. It allows you to be less a consumer of harmful products and more a resourceful gardener.

After reading about all you can get out of the liquid gold, I’ll bet you are just itching to know how to make your own, right? Well believe it or not it is and incredibly simple and easy six step process.

Compost Tea Directions:

  1. Fill a bucket 1/3 full of quality finished compost from you compost pile (or you can even use store bought compost, if you must.)
  2. Add water to the top of the bucket (unchlorinated is best, but pond or good well water work great. If you are using city water fill another bucket with water and allow it to sit in the sun for several hours so that the chlorine will evaporate.)
  3. Let the mixture steep for three to four days. Stir it now and then, not a set schedule, just give it a swirl occasionally.
  4. Strain the mixture through cheesecloth or other porous fabric (burlap, old shirt) into another bucket. Add the remaining solids to your garden or compost bin.
  5. Dilute the remaining liquid with water so it’s the color of weak tea (I use a 10:1 ratio of water to tea.)
  6. Use tea immediately for optimal absorption into the soil around plants.

Now, before we reach the end of this week’s article, let’s cover a few tips for using this magic elixir. First off when using it on potted plants or young plants you will want to dilute it down even more, say 20:1. But around the root systems of hardy shrubs, trees, or established plants in the vegetable garden, simply pour the tea from the bucket all around the plant. Next, if you want to use this as a foliar spray you certainly may. Just add about 1/8 tsp vegetable oil or mild dishwashing liquid per gallon to help it adhere to your plant’s leaves.

Keep in mind that unfinished compost may contain harmful pathogens and compost that is too old may be nutritionally deficient. compost tea and manure tea are not the same thing. Manure teas may be made in the same way but are not generally recommended as foliar sprays and are not as nutritionally well-balanced.

Recent research indicates that using some kind of aeration and adding a sugar source – I use ½ a cup of plain old molasses per gallon, though some folks I met in Waco swore by adding a full cup of cola per gallon – results in an excellent product that extracts the maximum number of beneficial organisms. Aeration is crucial to the formation of beneficial bacteria and the required fermentation process, so you must be sure to stir the mix as mentioned above. And finally, you can add all kinds of supplements like fish emulsion or powdered seaweed to the mix as this will convert your compost tea into a balanced organic fertilizer.

So, give your garden, your yard, and your houseplants a tea party and just watch how happy it make them, and how happy they will make you in return.

-- Joe Urbach is the publisher of and the Phytonutrient Blog. He has lived in the Central Texas area for over 30 years. Urbach is a certified Texas Master Gardener from Hays County and is currently serving as the director of training. For more information on the Master Gardener program contact the Hays County AgiLife Extension Service at 512-393-2120.

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