Saturday, September 14, 2013

Farming Worms

About a year ago a good friend of mine who’s a keen gardener living nearby, decided to move away from Auckland. He had a worm farm that he didn’t want to take with him, so he asked me if I wanted it. I had no hesitation in accepting it.

I’d heard quite a bit about worm farming over the years but never been that bothered about pursuing it, so I didn’t really know much about it, other than how the juice collected from the worms can be diluted and used to water the garden, with terrific results.

This particular worm farm is made out of black plastic. It has three levels and is raised up on legs with a tap attached to the bottom level, through which the juice drains into a bucket.

After determining a suitable spot for it under some trees in the shade I levelled out an area laying down some paving tiles for it to sit on. It’s best for it to be located in a place that’s in permanent shade. The worms themselves prefer to be in complete darkness much like their normal home under the ground. Apparently, they’re quite fussy eaters — they don’t like citrus scraps or onions or anything else that’s too acidic. We mainly feed them all our kitchen scraps but the worms especially seem to love the pulp that comes out of the vegetable juicer (my wife is juicing daily). They probably like it so much because it’s very easy for them to get stuck into, having already been minced up.
Before long the worms were producing huge quantities of juice. The bucket was filling up every 2 or 3 weeks. So we just transfer it into 3 litre milk bottles until we need it. Then I mix it about 10:1 in a watering can and pour it on the garden.
Things were going really well with the worm farm until one day we noticed something wasn’t right. When we opened the lid to feed them all the worms were massed together around the outside perimeter of the farm and appeared to be rather slimy and the sound they gave off was a sticky-gurgling-bubbling noise. We also noticed that quite a few worms had escaped (as pictured below) into the lower chambers which is not normal.
After doing a little bit of research we came to understand that this was a sign that their environment had become too acidic. We also learned that an essential part of their diet is carbon roughage usually in the form of paper or cardboard. 

At this point we decided to give the whole worm farm a complete clean out as the lower chambers were full of worm castings anyhow. This would be great for putting on the compost*. 

The picture above is of the bottom chamber. The picture below is of the top and middle sections. You can probably see there’s quite a marked difference in the consistency of the castings between the bottom and middle sections – the middle section is quite dry in comparison to the bottom compartment which is quite sloppy. The middle section was full to the brim with castings, so much so that the top compartment was sitting directly on the castings, so it was definitely time for a clean out.

So we  are conscious now of always adding a bit of corrugated cardboard cut up into strips and layered in with the food we give them because they also like their environment to be kept aerated. Since we did this they seem to be doing fine.

*As mentioned above. I put the castings and the sludge from the bottom compartment into the compost. As part of my normal compost routine I usually try to mix up the wet and dry ingredients that I have on hand. Eventually it will all even out into a nice crumbly consistency. I’m looking forward to seeing what difference the worm castings make to my compost when it’s ready to be used in the garden. 


  1. Hey this worm farm something your friend developed or something he bought. I find it fascinating because I have a makeshift worm farm my brother-in-law gave me when we move into our new home.

    I did not know the liquid could also be used. We are only getting casings but if that is the case then I need to put a spigot on that bin. Kinda explains why there was a tub underneath it.

    1. Hi Antone, yes this is a bought one. This particular model is not an uncommon sight in gardener's back yards here in NZ. It's a pretty simple concept so some choose to make their own.
      When I cleaned my worm farm out recently I put all the castings in the compost along with the worms that had escaped. I reckon that'll be a pretty good brew when it's ready.
      In the mean time the liquid (some call it worm "pee") can be used immediately.

    2. What would you suggest would be a ratio for the castings and soil? Because I heard castings itself is a very concentrated fertilizer.

    3. I'm not sure on the answer to that one Antone. I usually dilute the liquid 10:1 with water, but I'm not sure about the casting themselves. I added another pic to my post showing what I did with the castings. As you can see I didn't put it directly in the garden but on the compost instead.