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Low Cost Worm Farm ‘Tractors’ For Small Spaces

Worms may not have a backbone, but they are the backbone of our soil. In a suburban garden with no manure-providing animals, being able to dig into your composting worm farm for a handful of black gold is a real cost saver and loop closer. So giving some thought to how that worm farm fits into your overall Zone 1 system — as a time, effort and space-saving soil fertility provider — is time well spent.

This low cost worm farm tractor, or stand-alone worm farm set up, relies on a sturdy container that can be moved comfortably by one person, and remain intact while you do so. This is because you often have to move it in areas that are ‘standing room only’ in the confines of your urban plot. I now have four of the following worm farms, but the worms are breeding so fast on one family’s kitchen and garden scraps, cardboard, paper, and coffee grounds, that I’ll be adding another unit to my tractor soon.

The limitations to using the tractor setup are climate and shade coverage. For example in harsh Australian summers I can only put a worm tractor in my shaded beds or shaded service areas. Young systems will not have enough shade in summer, so find your best shady area and site them there. If you do so higher up in your backyard, your beds will gain from fertility flow if you leave the lower bowl component off to allow nutrient leachate to exit the bottom. For cold climate areas the farms go indoors into garage or basement in winter and there the lower bowl is a must, so there is no leakage from the unit.

These units can be used as a worm farm tractor or stand-alone worm farm.

Setup

  • Black plastic garbage bin with handles. Drill drainage holes in the bottom and two sets of 5 holes on top of each side of the lid.
  • Laundry basket with handles (fits inside garbage bin.) Drill holes in bottom.
  • Laundry bowl (no holes) fits inside the bottom of the garbage bin, under the laundry basket. As mentioned above, the bowl is an optional component, because you remove this if you have the worm farm in tractor mode in a garden bed, allowing leachate to drain straight into the soil through holes in the laundry basket and bin. Add the bowl for indoor use.

1. Line the laundry basket with dampened newspaper. The holey laundry basket keeps enough air circulating and the newspaper stops the worms climbing up and out, and the castings from going into the bowl.

2. Put your worm bedding material inside the dampened newspaper lining, then your worms, and let them settle for a day.

3. Cover the top of the worm/feed layer with dampened newspaper. I also include a dampened circular commercial cover (hessian wool blend) which helps to moderate moisture, then put the lid on the garbage bin and park in the shade.

Start introducing small but regular amounts of minced kitchen scraps (food processed) onto the top of the worm farm. Minced scraps reduce wasted space in the bin and help the worms turn the scraps into castings quicker. The resulting castings are even, for use in soil amending and potting mixes.

4. Avoid hot concrete paths or any surface that might cook the contents of your worm farm. Do not use metal bins either, for this same reason.

Advantages

  1. Parked at different convenient shady spots in your Zone 1 garden, and moved often, like a chicken tractor, the fertility drains straight into your garden bed. Over time, provided there is shade, whole garden beds can be improved.
  2. The worms survive even if they crawl out the drainage holes because they have their perfect home and kitchen to return to when they need it.
  3. As enclosed systems the bins move easily without dismantling or messy clean-ups. Some more independent young worms lurking outside the drainage holes can be scooped up and returned home before their parents knew they were out.
  4. The farms are easily lined up in a safe cool place when you go away, with no maintenance beyond a feed and dampening mist, if necessary, before you go.
  5. The whole farm can be harvested by lifting the inside laundry basket up by its handles, taking the newspaper lining out with worms in it, and leaving it in bright (not hot) light on a table top. The worms then shy away from the light and head to the bottom, after which you can harvest the castings from the top and put the worms back into the bin with new newspaper lining in the laundry basket and some new bedding.
  6. Mincing the scraps means the area to contain them is small; the worms get through them quickly (an advantage in small space worm farms).
  7. Disabled gardeners would find this system more manageable by reducing the size of the bin to suit their physical capacity.

In about a month you’ll have worm castings to harvest for garden amendments or potting mix components. You can ‘bandicoot’ handfuls to soak for garden foliar and soil sprays. The bowl collects excess worm leachate, which can be emptied on the garden or lawn as you choose at a high point in the backyard, to filter down with soaking. I prefer soaked castings to make my garden foliar and soil sprays.

Disadvantages

Well, I haven’t encountered any yet, in a 12 month-old system of four farms. This method is an improvement on the ‘chuck and forget method’ I used for 20 years with my worms breeding under-utilised in a compost bin directly on the soil in a shady garden spot. My new method helps me spread fertility around the garden evenly and effortlessly. The system is easy to handle, in small chunks, when I get time.

Use or adapt this idea to suit your own needs, and please let the rest of us know how you went in the comments section below.

Further Reading:

15 Comments

  1. I do something pretty similar. I use large (that I can carry) terracota pots in which I raise worms and move it here and there. Once I have a very healthy product, I mix it with soil and plant straight in the pot. This is how I bring pumpkins, chayotes or other creepers/climbers where I want them – balcony, patios…

    1. Really good idea Keveen. I like the way you are creating a mini ecosystem with the worms in the pot which you don’t disturb to plant, just like we try to do on a no till macro scale. Will be trying your idea for sure.

    1. Mine are red wrigglers Ilse. No idea of the scientific name as they are descendants from the first worms i purchased in 1991 when i was responsible for talking to schools about worm farms as part of my health promotion council job. We called them red wrigglers, thats it :)

  2. I do something similar, but just used 2 polystyrene boxes from the green grocer. the one on top of the other has holes in the bottom and a lid. Easy peasy. Got the info from abc.net.au gardening Australia program.

  3. this system is similar to one i use, except I half bury a bucket (drilled with drainage holes) in the ground. In our tropical climate this insulates the bucket from our extreme temperatures. I have two systems and alternate a spare bucket inserted into the top of the bucket. Once i start filling the top one with food the worms migrate, leaving the castings in the lower bucket. You could do the same thing by adding a spare laundry bucket to the top and let the worms migrate into the top.

  4. wonderful system, especially in depriving the local rats and mice access to the kitchen scraps, such a problem with so many other worm farm systems.

  5. A good way I’ve found to introduce larger, woodier parts to the worm farm is to “pre digest” them. I have an old wheelie bin that they all go into and I divert rainwater into it and keep topping it up as i take water out with the watering can for hand watering. Over the course of a few weeks a lot of the nutrient gets distributed into the garden via watering and the more fibrous plant parts soften enough to go into the worm farm or the the compost.

    1. Thanks for your lovely comments Mirrabooka and Fathi. Justin i like your idea of softening the woody fibrous material before putting it in the worm farm. It would make for more fungal content in the castings which is always good for the fruit trees.

  6. You know, for the last couple of years, I’ve wanted a small vermicompost container for faster and more convenient kitchen scrap composting in winter, but I never got around to building one because I couldn’t find the right kind of large, non-transparent plastic boxes. But now you’ve inspired me to just try it with a cement bucket and a large plastic flower pot with holes that fits in the bucket, and another shallow bowl-shaped pot as a lid on top. It’s too late in the year to mail-order worms where I live (the breeders don’t mail them below 10°C air temperature), but I collected a hand full in the garden. That probably won’t be enough to actually compost much of the kitchen scraps this year, but at least I’ll see if the system works in our warm utility cellar. And maybe the worms will even breed some, so I’ll have more to add to the new raised bed planned for spring.

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