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How to gain the most from your worm farm

Some interesting facts

  • Worms work upwards.
  • One kilogram, or 4,000 worms, cope with one kilogram of scraps every two to three days.
  • Grass clippings convert faster than food scraps.
  • Worms are just like us. Think of worms as pets - if you’re cold so are they; if you’re hot so are they. Store your worm farm in a sheltered place and keep your worms moist. Shade and moisture are critical for worms.
  • Worms hate solid rain as they think they are going to drown. When rain starts to set in, place dry grass, garden clippings or paper in the top of your worm farm to help them feel secure. Cover your worm farm over in constant rain or the worms will try to get out.
  • Smaller pieces of food break down faster. If you need your worms to convert a lot of waste quickly, you can soften the food in the microwave first. You can also add the water in which you cooked the vegetables, as the worm farm needs to be moist at all times.
  • Worms like a large surface area. They are photosensitive (don’t like light), so place an old piece of carpet or thick cardboard over the top of your worm farm to protect them.

What worms eat

Yes foods  Yes

Worms can eat the following foods:
  • most vegie scraps
  • all fruit except citrus
  • garden and grass clippings
  • shredded paper and cardboard
  • human hair
  • most manure (unless the animal has recently been wormed)
  • egg shells, however they don’t break down and are left in the vermicast, so crush them before adding
  • tea leaves
  • tea bags
  • coffee grounds.

No foods  No

Worms cannot eat the following foods:
  • meat or bones
  • grains or bread
  • dairy products
  • onion
  • garlic
  • tomatoes
  • citrus fruits
  • solid newspapers (shred or crinkle them first).

Things to consider

  • Always use rubber gloves and a dust mask when dealing with worm farms.
  • Mould can be present in the material breaking down, which could contain airborne bugs such as legionnaires disease.

Worms need a pH balance

  • Sprinkle garden lime or worm conditioner over the surface of the farm once a week to decrease acidity.


  • Do not load the farm with a large quantity of food if you’re going away as mould will develop.
  • Place larger pieces of food in the farm as it will take longer to break down (eg, whole apples instead of apple peel or core), and a little more lawn clippings and paper.
  • Make sure there is plenty of moisture (not muddy).


  • Ants will be attracted to the food too, however they don’t convert - they simply eat.
  • If you have ants around your worm farm, it is too dry.
  • Eradicate ants by using Borax, water or vaseline around the ant entry point.
  • Throw soldier fly larvae (they look like little armadillos) out for the grubs to eat as they don’t convert either.
  • If you have vinegar fly it means you are feeding your worms more than they can cope with.
  • If you have ordinary flies around your worm farm it is too wet.


  • Don’t overfeed.
  • Use lime regularly to balance.
  • Mask food smells with grass clippings – healthy worms do not smell - rotting food smells.

When choosing a worm farm

  1. Look at the capacity. How much food do you have to convert? Don’t get a small farm as they become too hot and aren’t worth the constant caretaking.
  2. Look for a farm with a larger surface area for quicker results.
  3. Make sure there is plenty of airflow – worms need oxygen.
  4. Don’t get farms that are too deep – worms can’t make it up to the next level and drown.
  5. Look for ease of use.

Vermiculture (worm farming) encourages native worms to proliferate.


  • Worms die
  • Too acidic
  • Sprinkle with lime weekly.
  • Lack of oxygenated material
  • Insert dry garden clippings and grass and, using rubber gloves, ‘fluff up’ the material at the top of the farm to get oxygen through it.
  • Temperature extremes
  • Place farm in a sheltered place.
  • Flies around farm
  • Farm is too moist
  • Add dry grass clippings and stop watering farm for a day or two.
  • Lots of ants
  • Farm is too dry
  • Add water to farm to keep moist but not muddy.
  • Mouldy food
  • Worms don’t like it
  • Remove mouldy food and place into the compost.
  • Worms leave home
  • Don’t like the food
  • Avoid meat, bones, garlic, grains, dairy, onions and citrus fruit, plus anything else that is regularly left and not converted.
  • It’s raining or about to rain
  • Place a cover over the farm and add dry clippings.

More information

If you need more information about worm farming, please contact Waste Services on: