How To Build A Worm Farm

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Build A Worm Farm

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Project Overview

Worm farms are a simple way of recycling fruit and vegetable scraps into highly fertilised soil (castings) for your garden. As your farm grows your garden may blossom from the enriched fertiliser.


Red or Tiger worms
Container of some description
Container cover, such as a plastic sheet
Organic food scraps


Drill and bits (1/4 inch) to make holes in the containers

Step by Step Instructions

1 Choose your worms
2 Choose a container
3 Making your own worm farm
4 What to feed the worms
5 Hints and tips
  • Step 1. Choose your worms

    Red and Tiger worms are recommended and are available at most nurseries.

  • Step 2. Choose a container

    Worm farms are basic 3 or 4 level structures which you can make yourself or purchase. You can use waterproof containers such as old wooden or polystyrene boxes, or purchase stackable worm farms with liquid run-off taps that allow you to collect waste which when diluted is great for distributing on your garden. Your container size determines on the volume of organic waste and the space your have available in your backyard.

  • Step 3. Making your own worm farm

    Line the bottom layer of your container with two sheets of newspaper, then fill the container half way with compost, grass clippings and moist shredded newspaper (see Fig 2).

    Add the compost worms (Tiger or Red worms). Don’t add too many as they will breed and grow in direct proportion to the feed provided and the size of the worm farm.

    Water till moist then cover the container with a garbage bag, plastic sheet a hessian bag.

    Starting with a small amount of food in the first week gradually increase this amount over the next 6 months. It is best to feed your worms weekly.

    After feeding the worms, cover the organic scraps with some compost or soil to avoid attracting vinegar flies.

    Add water every few days or when necessary (especially during hot spells) to prevent the worm farm from drying out. It is important to keep the worm farm moist, as the worms may die if it dries out. However, the worm farm should not be soggy either. Remember, there is moisture in the organic scraps.

    If the worms outgrow your container, simply remove the container lid and add another level on top of the original. Insert several holes (2cm wide) into the bottom of the container.

    With the new level, place food with compost to attract the worms to enter the new container therefore increasing your casting volumes. You can harvest your castings after a few months when the worms have relocated to the above level where the food is. Make sure to replace with new compost and start again by adding levels.

  • Step 4. What to feed the worms

    Worms will eat almost any type of fruit and vegetable scraps, coffee grounds, paper, leaves and even damp cardboard. Don't feed worms onions, and limit acidic food like oranges and lemons and avoid materials contaminated with toxic chemicals, such as treated wood. Try not to feed your worms meat, poultry, dairy products, or salty food like potato chips as these will attract insects, rodents and create odours.

  • Step 5. Hints and tips

    • Support the farm off the ground with bricks, making sure to tilt so that the liquid waste can be gathered. If your bedding is too wet, add some dry bedding, leave the cover off for a few days, or carefully drain the water off. If it is too dry, add some cool water and leave the farm loose-ly covered. More water may need to be added on hot, windy days.
    • Do not over feed the worms as over feeding can lead to odour prob-lems. If uneaten food remains simply wait until the scraps have been eaten before feeding.
    • As your worm population increases, you can add more food per day.

Please make sure you use all equipment appropriately and safely when following the advice in these D.I.Y. videos. You need to be familiar with how to use equipment safely and follow the instructions which came with the equipment. If you are unsure, you may feel it is safest to consult an expert, such as the manufacturer or an expert Bunnings team member.

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