Compost Tea

The Vintage Rosery

Needville, Texas

Have you tried Compost Tea in your garden yet? This concentrated liquid compost extract is teeming with live beneficial microorganisms, and is the best way we've found to 'feed the soil'. We now know that a healthy soil environment is the key to healthy plants. A healthy soil is one that is alive with beneficial microorganisms. These microorganisms are responsible for producing robust plants, more resistant to insect and disease problems and plants and trees that are more productive and able to withstand extremes in temperature and moisture.
Compost Tea will help your new plants get established quickly, with less transplant shock and faster root development. Compost Tea enhances the development of new roots as well. Existing plants and lawns benefit just as much from Compost Tea.
Plan on applying your compost tea the same day you pick it up. Fresh tea contains billions of microorganisms. It has a very limited shelf life and starts to decline after 36 to 48 hours.
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Every chemical-based fertilizer, pesticide, insecticide and herbicide tested harms or outright kills some part of the beneficial life that exists in soil. Compost teas, correctly made and applied, improve the life in the soil and on plant surfaces. Using compost and compost tea will increase the beneficial soil microorganisms and reduce disease-causing pest organisms.
By feeding the soil, we are really feeding the microbes in the soil because it is the microbes that make nutrients available for the plants. The way you feed microbes is through the addition of organic material. If you feed with a synthetic chemical fertilizer you are feeding the plant, not the soil, or the microbes. By using a petrochemical synthetic fertilizer we drive up the salt index in the soil and change the pH, which can have adverse effects on plants. More importantly, synthetic chemical fertilizers only feed for a short period of time. Organic fertilizers continually feed because the microbes cannot digest all of the organic fertilizer overnight. With synthetic chemical fertilizers we also do not get the benefits of the microbes contribution to soil aggregation, which leads to good tilth, water retention, water penetration, oxygenation and reduction of runoff.
Foliar or root applications of compost tea provide many benefits. These can include:
No black-spot or powdery mildew. A foliar spray of the leaves prevent pathogens from infecting the plant tissues because infection sites on the plant surfaces are occupied by beneficial organisms. Also, these beneficial organisms eat the food (exudates) disease-causing organisms require.
Increased plant health. Soil structure is improved allowing more oxygen to reach the root system, preventing toxins from being produced in the soil. Rooting depth of the plants is increased, increasing the nutrients the plant can access.
Increased drought tolerance. Water-retention in the soil is improved, reducing water use by up to 50% in two years in some cases.
Chemical-based pesticides, herbicides and fertilizers are no longer necessary.
There has been some confusion over the definition of compost tea. It is quite different from 'compost extract' or 'manure tea'. In summary, compost tea is a water extract of compost that is "cold" brewed. Beneficial organisms are extracted from vermi-compost (i.e. bacteria, fungi, protozoa and nematodes) and are "fed" nutrients to rapidly increase their numbers and activity levels. Starting with a high quality biological compost, the resulting tea should provide an enormous amount and diversity of beneficial organisms.
'Compost extract', on the other hand, is produced by running water through biological compost or letting compost steep for several days in a barrel or trash can. This water contains soluble nutrients, but very few organisms.
'Manure tea' is a water extract of manure. The result can contain soluble nutrients, high nitrates, salts, phosphorus and potassium. It can also contain high numbers of harmful bacteria unless there has been an antibiotic used in the animal feed. It often contains root-feeding nematodes and almost always contains human and animal pathogens. Manure tea typically contains E. coli, since manure comes from mammalian digestive systems and can also harbor Salmonella and Shigella. Manure is not compost.
The process of brewing compost tea must stay aerobic. Non-beneficial organisms can grow more rapidly in reduced oxygen conditions. Anaerobic teas can result in the growth of some particularly harmful bacteria and is not recommended. Aerobic compost tea does not contain human pathogens.
Frequently Asked Questions About Compost Tea
How far down in the soil does the tea move? That depends on the soil texture, compaction and the amount of organic matter in the soil. The sandier the soil, the further down the tea (and organisms) will move. The heavier the clay, the more the tea stays at the surface.
How frequently should I apply tea to my garden soil? That depends on the plant, the soil, the seasonal cycle and what you hope to accomplish. Typically, compost tea should be applied once a month during the growing season. During times of plant stress (known disease, environmental stress, etc.) increase application to as frequently as every week.
What is the dilution rate for foliar applications? For preventive applications, we use a 50/50 ratio (water and tea) and spray the leaves top and bottom every two weeks during the spring and fall. If disease is observed, we spray undiluted once a week until the disease is controlled.
What is the dilution rate for soil applications? There are several big IF's in this answer. IF the soil is chemical free, apply one quart per 1,250 square feet. The dilution ratio is not important as long as the quart is spread over the 1,250 square foot area. A soil test is the only way to determine what organisms are in your soil and whether they are active. If you are having problems, have your soil tested. If the soil test shows a problem, the solution is normally to add additional compost and compost tea. So, assume the worst and apply it.
Once your soil has a variety of organisms, they need to be fed. Molasses (sugar) will feed beneficial bacteria and kelp or humic acids will feed the fungi. See our Organic Lawn Care page for more information on soil and treating specific soil problems.
How quickly must I apply compost tea? ASAP. Because this tea is a concentrated solution teeming with life, it is very perishable and should be used within 6-8 hours of 'brewing', although in the soil these organisms can keep on working for months. There will be  microorganisms alive for 12 to 48 hours, but in reduced quantities. Call us a day or two before you plan on coming to make sure we will have a fresh brew the day you plan to use it. You may reserve a gallon over the phone.
How is compost tea applied to my lawn and garden? Water is used to dilute and disperse compost tea. A simple hose-end sprayer works well for us, as does a pump sprayer. We recommend using the type of hose-end sprayers that have a dial on top. Fill the container, set the dilution rate somewhere between 4 and 7 ounces per gallon and spray until empty. Repeat the process until all the compost tea has been used. A higher dilution rate is fine. The purpose of using water is simply to disperse the live microbes. For small gardens, set your sprayer on the highest setting.
Tip: Remove the screen filter from the hose-end sprayer located at the end of the plastic tube. The mesh is too small for the microbes to pass through.
Alternatively, a pump sprayer can be used. For larger areas, we use a small tow-behind spray tank attached to our riding mower. It has small booms for spraying a wide swatch of yard as well as a hand-wand for spraying targeted areas. The one to four gallon hand pump sprayers will also work.
It is best to apply in the early morning or evening hours to prevent the tea from evaporating in the afternoon sun. In fact, the best time to apply would be just before or during a rain shower allowing nature to water it into the earth.
A word of caution. When using water from a city municipal or MUD district that has been treated with chloramine, do not use a hose-end spray attachment as it will kill many of the microbes in the tea.
Throughout the U.S., chloramine (a combination of chlorine and ammonia) has been added to the public water systems as a disinfectant. Chloramine will kill the beneficial forms of bacteria in the compost tea. Unlike chlorine, it remains in the water through an aeration process or letting it stand overnight. It must be neutralized by adding a water conditioner.
Since chloramine can be deadly to fish, most fish and pet stores carry water conditioners. One brand is Tetra's AquaSafe. It is labeled to neutralize chlorine, chloramine, ammonia and various other chemicals. Apply per the label, which should say 1 teaspoon per 10 gallons. Using the neutralized water, dilute your compost tea in your pump sprayer.
Once the tea is ready, will continued aeration keep the organisms alive? Yes, but only for a short while. Research has shown that at the end of three days, a ten-fold reduction in organism numbers and 90% reduction in activity occurred. One study attempting to extend the shelf life of compost tea continued to add food along with constant aeration. At the end of five days, a serious reduction in diversity of the organisms was found. Adding food resources tends to out-strip the ability of aeration to maintain aerobic conditions. These teas would be less likely to benefit plants than younger, more diverse teas.
Does compost tea smell? Absolutely not. If there is any foul odor in a compost tea, something went terribly wrong during the brewing process, or the ingredients were bad. Foul smelling tea should not be used as it could be toxic to your plants.
Where do I get more information on compost tea? Dr. Elaine Ingham has done the most scientific research on compost tea. Her company, Soil Foodweb, Inc. tests compost, soil and the quality of tea and tea brewers. Here is a link to her firm's page on How to make Actively Aerated Compost Tea.