If you use worm for composting then it is likely you have heard of Leachate, Worm Tea and compost tea.  Often times, these terms are incorrectly used interchangeably, these are not the same thing!  


Leachate - The liquid run off (or seepage) that settles in or below the vermicompost or worm castings. Check for accumulated leachate in your vermicomposter frequently (when you feed, or weekly).  This is the liquid that runs out of the bottom of worm bins.

Worm tea - The end result of suspending worm castings in highly oxygenated water (brewing).

Compost tea - The end result of suspending compost in highly oxygenated water (brewing)

What is worm tea?
Worm tea is known mostly for its ability to boost microbiological activity in soil by adding bacteria, fungi, actinomycetes, and protozoa to the soil. It is brewed by either soaking a porous bag full of worm castings in water or simply dumping the castings into a container of clean chemical free water. Molasses (a food source) is then added to the water as a catalyst to stimulate the growth of the microbes. Then last, an air pumping system is installed to increase anaerobic (oxygenated) environment for the inoculation of the microorganisms.

Worm tea is beneficial in so many ways. The microbes delivered in worm tea help plants by out-competing anaerobic and other pathogenic organisms and by occupying infection sites on plants' root and leaf surfaces.

The purpose behind creating worm tea is to speed up the growth rate of microbes such as bacteria, fungi, protozoa, and nematodes, and to multiply their numbers exponentially. One reason for applying the tea to your plants is that it is absorbed more rapidly by the plant than castings, which are released over time.

When you spray or pour the tea on the soil not only are you feeding the plant, but you increase the number of beneficial microbes in the soil, thus crowding out the bad. It has been proven that the tea, along with the castings, can significantly increase plant growth, as well as crop yields, in the short term (a season) and especially the long-term over a period of seasons.

Along with these great benefits come a boost in the plant’s own immune system to be able to resist parasites like the infamous aphid, tomato cyst eelworm, and root knot nematodes. Plants produce certain hormones (like the jasmonic hormone) that insects find distasteful so they are repelled. Worm tea also helps a plant to resist diseases such as Pythium and Rhizoctonia.

When worm tea is sprayed on leaves and foliage, the bad disease-causing microbes are again outnumbered and cannot populate to the levels of taking over a single plant. The tea also aids the plant in creating the "cuticle", a waxy layer on top of the epidermis, or plant skin. This waxy surface protects the leaves from severe elements and reduces attacks by certain harmful microorganisms and insects.

Compost Tea -
Making an organic compost tea involves several important steps 1) choosing the right compost, 2) choosing the right nutrients and 3) brewing and applying tea correctly. Our instructions here are only meant to give you some background to tea making.

The compost used in making tea is like the starter you use in making yogurt or bread. The compost inoculates the tea with organisms. Thus, you want the compost you begin with to have a good diversity of beneficial organisms!

Plants differ in their soil preferences. Some need a bacterial-dominated soil, others want a fungal-dominated soil and still others like a soil that's somewhere in between.

To make an organic compost with more fungi, mix in larger amounts of cardboard, paper, sawdust, wood shavings and heavy stalk plant material as you prepare the compost. For bacterial dominance, use food waste and green plant waste. Whatever compost you use, be sure it is finished, well-stabilized compost, and that it's fairly fresh.

Always use only dechlorinated water, rainwater, pond or distilled water.

Brewing nutrients also influence the finished tea. To encourage the development of fungi in the tea, mix two parts humic acids, two parts yucca, saponin or aloe vera and one part fish hydrolyzate or other proteins into the water. For bacterial dominance, you'll feed one liquid ounce black strap molasses per gallon of tea and an equal amount of cold-water kelp. For the molasses, you can also substitute brown sugar, honey or maple syrup if you like.

In both, microbiology is extracted from the microbial seed material with water so that the microbiology is a liquid solution which can be sprayed – most often a far more convenient and feasible application method than bulk soil amending or dispersion.  The nature of Worm Compost Tea vs. compost tea can be radically different with Worm Compost Tea having more species diversity and worm created substances than compost teas and therefore offers more effective results.

There are two types of Worm Compost Teas: extracted and aerobically brewed.  In the extraction method, water is run through the earthworm castings to simply extract the microbes from the castings into the water. The resulting liquid solution is then applied in various ways.  Many bottled teas you see on the shelf use this method.  In the brewing method (what we consider to be the BEST method), worm castings are placed into a container of circulated and aerated water (via an air bubbler or similar system) typically with other nutrients listed above.  The circulated water extracts the microbiology and the microbes are in an abundance of both oxygen and nutrient to feed upon.  In this method, colonies of microbes are brewed in exponential numbers, a colony of bacteria, for instance, can double in population every 20 minutes.  Aerobic brewing takes longer than basic extraction with common brewing times of 12 to 24 hours.  Brewing time is very dependent on water temperature with warmer water creating faster brews.  Aerobically brewed teas have much higher microbe population densities than extracted teas and for this reason are the tea of choice.  The sign of a good aerobically brewed tea is a good head of foam and scum on top signifying healthy microbe action!

How Worm Compost Tea works
Worm Tea is all about microbiology and is measured and evaluated under a microscope.  Compost, worm castings and other inoculants all work and are evaluated by this means also.  It is the wide diversity and numbers of microbiology that define a good tea. Worm Compost Tea is important to the healthy soil which, in turn, creates healthy and vibrant plant life.  

Worm Compost Tea suppresses disease and pests on vegetation and will boost the crucial microbial activity known as the Soil Food Web (SFW) which is so crucial to organic soils.  Perhaps the most widely used and known use of teas is to suppress/eliminate black spot and powdery mildew on roses.  By spraying Worm Compost Tea on the surface of leaves, you are doing two things.  First, you coat the leaf with millions if not billions of microbes all competing for a food source.  Some, for instance, protozoa, eat bacteria which may be eating decaying plant material.  Others eat other microbes and their wastes.  In the end, there are not enough resources for the harmful molds and fungi to flourish.  In addition, you are also coating the leaf with a protective surface that protects the leaf cells from attack by foreign spores or airborne microbes.  Finally, by inoculating the soil with Worm Compost Tea, microbes break down nutrients for uptake into plants thereby increasing plant health and the plant’s own disease resistance/suppression.

Aerobically brewed Worm Compost Tea is superior to basic compost teas because of the higher number and diversity of microbes, the additional substances that worms create and the reduction or lack of harmful microorganisms.  Although a traditional compost pile is a great environmental aid, and its final compost is a great value to your garden, it typically does not have the microbe species diversity and numbers of worm castings – especially when using Red Worms Express Organic Earthworm Castings – to be an exceptional aid.  (Remember, microbial species diversity and numbers are necessary for a more thorough breakdown of the organic matter in any compost.)  A tea can only have the species diversity of the starting medium.  The only way to circumvent low the numbers and diversity when brewing tea with a basic compost is to inoculate the tea itself during or at the end of the brew with catalysts, i.e. microbe packages!  Worms also create substances that act as growth hormones, cell length regulators, anti-aging compounds, and more goodies that just are not available in common compost.  Though different in quality either the brewing or extracting method will add these important aspects to teas, and this is the probable explanation of good results obtained by non-aerobic bottled tea that does not have high species diversity and numbers.  Finally, compost can also contain E.coli and other human pathogens if not composted properly.  In aerobic brewing and with adequate aeration maintenance, E.coli will not survive in the tea, because “there are many other organisms, which in aerobic conditions, grab food away from the E. coli, take up the space E. coli needs to grow, and consume E. coli.”  (2003, Dr. Elaine Ingram)   (An important note here:  “If you apply a source of questionable material anytime 120 days before you are going to eat those vegetables without washing them, there’s a possibility that E.coli could still be present, especially if your crop production system does not have adequate aerobic organisms to out-compete the coliforms.”  (2003, Dr. Elaine Ingram).

How to use Worm Compost Tea
Spray your plants liberally on the leaves, stems and surrounding soil.  Use them on turf.  Use them on clay soil to begin its transformation to humus.  Use them on your flowers indoors and out and on your other house plants. Use them on your compost pile to introduce the microbial activity and hasten the compost pile’s beneficial breaking down process.  Inoculate the ground surrounding your fruit trees.  Use them on manure piles that stink and marvel at how fast the stink and flies go away!  Use them on the small bucket of kitchen scraps you may have outside of your house.  Worm CompostTea everything!

Foliar Spray/Wash:
It’s best to spray all surfaces of your plants in the early morning or late afternoon when the suns angle is low and has less strength.  When possible do your foliar spraying on a foggy, cloudy or clear days since rain may wash away some of the effectiveness. 

Soil Inoculant - Drenching:
Always apply teas out of direct sunlight.  Use them pure or dilute them (10:1 is a suggested maximum dilution rate).  Dilution ratios vary due to the manor or the characteristics of your application technique or equipment.  An ideal time is during light rains, mists, or fog.  Alternatively, irrigate a little before your treatment and after the application to insure the microbes will survive and travel more quickly and safely to their new job locations. Whenever possible use non-chlorinated water.

If a tea stinks, do not use it on your vegetables as it is demonstrating anaerobic properties and may contain pathogens.  Dr. Ingram suggests you use it on an undesirable weed bed!

A properly brewed Worm Compost Tea is a child, pet, and wildlife friendly.

When we brew, there is a window of optimal application time when microbe populations and diversity are at their highest.  Best results occur when the Worm Compost Tea is applied during its prime and is applied within 3 hours of being removed from the oxygen source.

Leachate can contain phytotoxins (toxins that can harm plants and humans). Some of these toxins are created by bacteria. Every worm bin has good and bad microbes. This is ok of course, as long as the good ones outnumber the bad ones. Some leachate can contain harmful pathogens because it has not been processed through the worms intestinal tract. It should not be used on edible garden plants.

During decomposition, waste releases liquid from the cell structure. This liquid or leachate seeps down through the worm composter into the collection area. The leachate should be drained regularly and if you are getting more than 2-4 ounces of liquid in a week, the composter is probably too wet! We recommend leaving your spigot open with a container underneath to catch the leachate to avoid having it build up in your system. Just keep an eye on it to make sure your container doesn’t overflow!

While leachate can have value as a liquid fertilizer it should be treated with caution. For every story extolling the benefits of using leachate, there is one lamenting the problems from having used it. If you decide you want to use the leachate we recommend taking some extra steps.

DO NOT use it if it smells bad! Pour it out on an area where it cannot harm living plants like a roadway or driveway.
Dilute it ten parts water to one part leachate (10:1)

Aerate it with an air pump if available.

Use it outdoors on shrubs, ornamentals or flowering plants only. DO NOT use on plants you intend to eat.