Using Worm Castings

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Instructions For Worm Castings

Leachate (“Worm Tea”)

Aerated Castings Teas

Castings Extracts


Terminology: Worm Castings Vs Vermicompost

To use the correct term, the material from a worm farm should be called “vermicompost”, or “VC” for short (Details below)


Storage Of Vermicompost (“Worm Castings”)

*** MOST IMPORTANT: Vermicompost should be treated like a worm farm:

It MUST be kept in a cool shady spot, preferably out of the sun, or heavily protected from the sun by more layers of bags, cardboard etc.

VC must be kept moist

They must not be sealed into an airtight container

They should be used at a maximum application of 20% to 25% of the volume of the soil. Any more and they do LESS good than at the ideal application rate.

Screening Of Vermicompost (“Worm Castings”)

There may be small lumps of material in the castings (unless you have bought screened castings from me, in which case I run them through a 6.5mm screening unit) – these lumps in my opinion are beneficial to the garden – they may have worms or cocoons in them – screening takes out any remaining worms in the castings, and only makes the castings look better.


Application Of Vermicompost (“Worm Castings”)

***** CAUTION Re Using On Edible Leaf Plants – Re PATHOGENS *****

Do NOT Use As A Foliar Spray On Edible Leaf Plants,

and do not broadcast VC onto these plants.

Carefully place the VC on the soil only, or use ACT only on the ground as a drench

(As A Precaution against pathogens)

The caution is that if there are pathogens in the VC, especially from un-composted animal manure inputs, or uneaten foods, that there could be pathogens in the VC.

Do not apply on leafy greens/ vegetables youre going to harvest to eat (use ground drench only on these gardens, being careful not to get it on the edibles. This is a simple precaution)


Using The VC Itself, In Gardens, Plants In Pots Etc:

– VC may be applied to the soil around existing plants at a rough rate of a handful per plant, agitated into the soil then watered in.

– VC may be used to mix up soil for a garden, plant pots or seed germination/cuttings.

For these purposes addition of approx. 20% (1 part to 4 parts other soil mix) is sufficient, and has been tested by many as being the ideal amount to use.

Using more (than 30%) gives worse, and at times MUCH worse results.

Remember the value is in the MICROBIAL content of the material and its inherent properties as a soil CONDITIONER – NOT the value of its N-P-K.


The VC Can Be Used To Make “Actively Aerated Castings Tea” AKA “AACT”

It may be steeped in water, in a particular fashion – some using a system called “Actively Aerated Castings Tea” (See notes on website) – where water, a little VC and at your choice other additives, are aerated by, most commonly, an aquarium pump and air stone. The resulting liquid is diluted with between 1 and 10 parts water, and may be used as a foliar spray or a soil drench. Dilute 1:1 to use on the soil or 1:4 to spray on foliage. It can be diluted up to 1:10 for either soil or foliage if you need it to go a lot further (i.e. you have a lot of land/garden and too few castings)

(For Instructions On This See My Website)

The “Leachate” AKA “Worm Wee” AKA “Worm Tea”

The leachate is the liquid that drains from some worm farms.

This is a contentious issue.

Some believe it to be bad for plants, some swear by it.

Perhaps those who had bad experiences with it may have not used it in the best way.

Personally I’ve never found any issues using it as directed.


How To Best Use Leachate:

(Leachate is the excess liquid that drains from a worm farm)

– Do NOT generate leachate on purpose, or excessively – putting a lot of water into your farm makes the conditions bad for your worms, namely reducing oxygen (anaerobic conditions), ruining the structure of the worm farm (turning it into a sloppy wet mess); it could also help increase acidity/ammonia and alcohols in the bedding by the nature of the bad conditions.

– use FRESH – do not allow it to build up for months – use it weekly. It spoils / goes anaerobic.

– do not store it in a closed container. It spoils/goes anaerobic

– dilute with 10 parts water

– do not use ON plants, but as a soil drench

– use it around ORNAMENTAL plants only


What makes VC better than traditional compost?

While both break down organic materials, the worms impart extra things to the VC as noted in the material above.

VC may bring enzymes, micro organisms, microbes and humus, the worms mucus, and the bacteria and microbes from the worms’ gut and the from the process of converting materials while in contact with the worms, their secretions and bacteria.

Worm Compost Information – Why Is It Good


“What IS Worm Compost AKA Vermi Compost AKA Worm Humus

AKA Worm Manure AKA Worm Castings”

(Shortened to “VC” in the following literature)


What IS Vermicompost – and why isn’t the term “Worm Castings” completely accurate:

Basically, VC is the resulting finished material, from a composting worm farm.

VC consists of the manure OF worms – “castings” (or “worm poo”); and any other material that may not have actually been EATEN by the worms, but has decomposed WITH the castings of the worms. This unfinished material could be some fine leaf or bedding, or some unprocessed food.

You would need to examine each piece under a microscope to call it ALL “castings”


What are some of the things the worms are fed (briefly):

– “bedding materials” – AKA “browns” (usually materials high in carbon, eg cardboard, newspaper, old leaves)

– “food” – AKA “greens” (such as kitchen scraps)

Some materials are considered both food and bedding, such as aged or semi composted grass clippings.

My worms are not fed any manure (ever) – they are fed cardboard, newspaper, aged grass & leaves, and kitchen waste (fruit/vege scraps).


What Sort Of Worms Are Used

The common worms to process material in this way are “composting worms”.

They are surface dwelling worms (called “epegeic” to be technical) – NOT deeper dwelling “earthworms” (called “endogeic” or “anecic” worms)


The most common in use are:

– Eisinea Fetida/Andrei – AKA “red/tiger”, brandling, manure

– Eudrilus Euginae – “African Night Crawler” AKA “ANC”  (A GREAT fishing bait – more suited to growing in warm climates)

–  Eisinea Hortensis – “European Night Crawler” AKA ENC AKA Euro (A good fishing bait – more suited to growing in cold climates)

– Pieronix Excavatus/Spenceralia – “blue”, Malaysian blue (PE in the USA, PS in Australia)

A mix of these worms is considered acceptable in Australia.


Benefits of VC:

There are MANY benefits.

A few are:

Benefits For The Soil:

– contains water soluble nutrients (is a “low value” of N-P-K – the benefit is not in the NPK value alone)

– it may hold moisture better than “plain soil”

– may improve soils ability to hold water

– may improve structural properties, aeration and porosity

– may reduce the level of some contaminants in the materials “input” into the farm

– it contains worm “mucus”, which may help keep nutrients from washing away

– may be considered an excellent, nutrient rich soil conditioner

– may have a higher saturation of nutrients than the material input into the farm

-it may enrich the soil with micro organisms, bacteria and fungi

– may increase the microbial activity in some soils by as much as 10 to 20 times

– will also help attract deeper dwelling “garden worms” to the garden ( endogeic/epeceic worms)


Benefits For Plant Growth:

– may improve root structure and growth

– may enhance crop yields, germination and plant growth

– may be a slow release material, and be available for a longer time


Benefits For the Environment:

– domestic worm farming helps reduce materials sent to landfills, saving the earth, and also saving the community money by reducing landfill need and garbage collection services.

– It helps to divert, in particular, material sealed in plastic bags which when sent to landfill do not decompose back to the earth, but make methane gas, which adds to the greenhouse effect

– Domestic worm farms use other common materials from the house and yard such as paper, cardboard, leaves, grass

Households with worm farms seem MUCH more in tune to recycling in general.


Thanks and happy gardening !!!


Brian Donaldson


[email protected]

0419 419 572