Worm Farming

The importance of worms has been noted as far back as 51BC when Cleopartra made exporting worms from Egypt a crime punishable by death.  Wormfarming, also known as vermiculture or vermicomposting has only really been around since the 1970’s.  Worm farms produce vermicast (worm castings) and worm wee (also known as worm tea or worm rum)

Worm farms in Education

Worm farming is a great project for schools!  Getting the kids to separate their waste and feed worms not only teaches them about sustainability but can save the school 20% -40% on their rubbish removal bill.  An old bath tub is great for schools.  (Bearing in mind it will need somewhere between 1kg – 3 kg of worms to get it started). Northland Regional Council have a fantastic page on this which can be found here.

Worm Porn

Adult worms can mate every 10 days and produce a cocoon of 1 to 20 spawn (baby worms).  They will never out-breed their available food source.

Worm Facts
  • If a worm dries out it will die
  • Tiger worms live between 6 months to 2 years
  • Worm cocoons are smaller than a grain of rice
  • The largest worm ever found was in South Africa, it was 6.7 metres long!
  • A Tiger worm can consume it’s own body weight in food each day.
How to build a worm farm

273690xlgCommercially made worm farms can be purchased and range in price from $120-$400.

However, they are fairly easy to make once you understand a few basic concepts and can be made out of practically anything:  An old bath, tyres untreated wooden boxes, drainage tubes…  the possibilities are endless, so use your imagination.

Before you begin there are four things to think about:

  • Drainage – you don’t want your worms to drown
  • Aeration – worms need air
  • Rodents – you want to make your farm safe from pests
  • Depth – worms need room to move.

Here we are going to work on the premise that you are using (rather boringly) plastic bins (fish bins).  A good size is 500mm x 500mm x 500mm.  However you may want to go smaller or larger depending on your family/waste size.

Your basic 3 bin worm farm consists of a bottom bin, where worm tea collects, this can be fitted with a tap (Plastic taps are available for around $12) which makes the worm tea collection easier.

The middle and top bins should have 6mm drilled across the bottom in a grid about 50mm apart this will allow the worm wee to drop through to the bottom bin.  A further line of holes about 100mm down from the top of the bin will help with aeration.

Place a packer (not treated wood – a clean brick will work well) in the bottom and middle bins to space out your bins (about 150-200mm).  You can block any gaps that appear between bins with shade cloth to prevent other insects from getting in.

You want to sit your bins in a shady location, it can be helpful to tilt the bins slightly to allow the wees to collect by your tap for easy collection.  (Worm wee will need to be diluted on a ratio of 1:10 before adding to your garden).

Populating your bins:  In your top bin place shredded newspaper (NOT glossy stuff), a little compost, and your wiggly little helpers.  Give them a couple of days to settle in then start adding food (see below for what to add and what not to add).  Once the top bin is full, switch it with the middle bin – again add shredded paper to this as you did with the top bin and some castings from your full top bin.  You can start using this bin straight away.

Once your worms have migrated up into the top bin (which was the middle bin) you can harvest the castings from the middle bin (which was the top bin) and these can be added to the garden.

On average you’ll probably be switching bins, replacing bedding every 3 to 6 months.

In hot weather you may need to add water.

If the worm farm becomes too wet however – add some dry bedding (newspaper, cardboard etc) and leave the cover off for a few days to help dry it out a little

If you seem to have a lot of food left wait before adding more.

If you are building your farm from tyres – don’t put it on corrugated iron as some websites recommend.  This will attract flies.  Just place the tyres directly onto the ground.

Feeding worms

Ideally food should be in small pieces.

Worms like But not
  • Newspaper
  • Crushed egg shells
  • Vacuum cleaner dust
  • Rolled Oats
  • Weeds
  • Lawn clippings (allow to cook off first so as not to overheat and kill your worms)
  • Peat moss
  • Carpet
  • Dead leaves
  • Tissues
  • Hair
  • Rhubarb leaves
  • Tomatoes
  • Citrus – lemons, grapefruit etc
  • Onions
  • Garlic
  • Treated wood
  • Salty food
  • Pineapple

Also avoid meat and dairy as this might attract rodents

Dos and Don’ts of Worm Farming
  • Don’t let your worms bedding dry out – if it is not getting enough moisture fromt he food added – add some.
  • Don’t let them get too wet – worms are not known for their talents as Olympic swimmers.
  • Avoid coloured/glossy paper in their bedding
  • Don’t put their dinner in the same spot.  Exercise your worms by rotating your food placement around the bin.