Brewing Worm Tea

“God gives every bird his worm, but he does not throw it into the nest.” ~ P.D. James


If you have read a bit of my blog, you will know by now about my borderline obsession appreciation of worms.

My worm bin is slowing down a bit in the cooler months.  It has not needed much water, so it is not producing much leachate.  Leachate is the stuff that dribbles out of the base of your worm farm.  As long as it is clear and doesn’t invoke a gag reflex with the smell, I have diluted it 250ml:9 litres and found it a wonderful garden tonic for the veggies.  However,  leachate is often confused with worm tea.

Worm tea is extracted from the worm castings, which are dunked in water (like a big teabag) and usually brewed for 24 hours or so with a oxygenator and a slurp of molassess or honey to feed microbes.

Advocates claim that worm tea is superior to leachate and chemical fertilisers because ;

  • it is a natural repellent for scale, mites, white flies, and aphids,
  • it is a natural fungicide in soil and on plant surfaces,
  • increases  plant stem size and foliage,
  • is a soil conditioner,
  • does not burn plants,
  • it aides in the creation of colloidal humus and
  • improves water retention in soil.

Sounds good, right? So I decided it was high time I gave making worm tea a go.

A quick trip to my local Big W sourced a small aquarium pump, a length of tubing and an airstone to oxygenate the water.  These set me back about $20.00.  When I got home, I searched the web to find a solar pump that could so the same job for approx $70.00.  If the worm tea proves beneficial, I might switch to a system that doesn’t use mains power.

A few lady-handfuls of worm poo

I made my big worm teabag.  A generous few handfuls of worm poo (castings) with all the worms picked out was wrapped in a clean dishcloth and tied with twine.

I submurged the worm tea bag into a bucket of rainwater along with the airstone and a teaspoon of honey and flicked the switch.  I have set mine up off the ground where it can’t be reached.  Even though I can secure my greenhouse gate, I don’t like leaving big buckets of water around for the kids to explore.

Then, I waited 24 hours.  Occasionally I checked on it and gave the teabag a bit of a swish around the water.

The worm poo teabag, ready to be submerged

The resulting tea didn’t really resemble leachate.  It was almost clear, with some sediment on the bottom.   It had no smell at all.   I decided not to dilute it and splashed it about the seedlings and newly planted beds.  Apparently, you have to use the tea within 4 hours of removing the airstone before the microbial population diminishes.  To be fair, the worm tea didn’t kill my seedlings.  But it remains to be seen if my worm homebrew really does anything better than a drink from the hose.    I am a bit suspicious!  Maybe warmer water and weather would help.

The “teabag” submerged, with the airstone positioned underneath.

I  will continue to make batches and spread it around.  When using water from the hose, I let it sit overnight to let the chlorine evaporate before submerging the teabag.  Yes, I have been using a new pouch of worm poo each brewing.   I mix the spent castings in with my seed raising mix.

If, in a few weeks time, everything looks like it needs a good dose of manure, I’ll know my worm tea has been a bit weak.

So, can anyone tell me what I might be doing wrong?

UPDATE: I think the washcloth net was too fine for the worm poo to steep.  I might have tied the package a bit too tightly, restricting the flow of the worm poo.  So when the zip went on one of my laundry delicates bags, I decided to recycle it into worm-poo-bag.  It made a huge difference having the bigger holes.  After 24 hours, the resulting worm tea was lovely and dark, with a little sentiment on the bottom.  It didn’t smell.  So I diluted it 1:9 and splashed it about.

So far, so good.  Even the weakish tea showed results.  I’m convinced that it will be worthwhile keeping a constant “brew” on the go all the time.




  1. Liz says

    It may be a little late to respond to this, but I just found you. What you did wrong is to use honey, which has antimicrobial properties. You should feed your bennies with a dash of molasses or maple syrup or brown sugar.

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