Arron Wood

Sustainable Business and Education Leader

Worms – a great garden recycler!

Previous research by The Australia Institute showed that Australians throw away about $5.2 billion worth of food every year. This includes $1.1 billion of fruit and vegetables.  The sad news is that things haven’t gotten better, they’ve got worse.  The best thing to do is not waste food in the first place and I’d strongly encourage you to head here for awesome information http://www.lovefoodhatewaste.vic.gov.au/

Here’s some amazing stats courtesy of the Love Food, Hate Waste website:

• The average Victorian household throws out $2,200 worth of food each year – that's $42 per week!

• One fifth or 20% of the yearly grocery budget is wasted on average. That's like throwing out 1 in every 5 bags of food you buy!

• Victorians collectively throw out $4 billion worth of food each year – that’s enough to feed 367,000 families for a year, based on a weekly spend of $207.

• Victorians throw away $700 million worth of leftovers per year – that’s enough to buy laptops for 580,000 school children

For those unavoidable food scraps instead of sending them to landfill why not keep a worm farm and let them do the work. Feeding fruit and vegetable scraps to earthworms is a cheap and simple way of recycling food and garden waste.  Worm castings make a really good fertiliser for gardens and worm farms are great for people in homes with small backyards and can even be kept on the balcony of a flat.  You might also like to think of keeping a worm farm at the office for lunch scraps.  The Adelaide Convention Centre even has an industrial scale worm farm to deal with food scraps from major events.

Worms will eat almost any type of vegetable and fruit scraps, coffee grindings, paper, leaves and even damp cardboard. Do not add too much acidic food like oranges and mandarins and don’t add any onions – worms don’t like these!  You should also be careful not to add anything toxic such as wood shavings from treated pine because this will poison your worms.

Compost worms are particular species of worm and popular compost worms include Tiger Worms, Red Wrigglers and Indian Blues and they can eat about half of their body weight in one day as they are generally more active than normal earthworms.  The population in a well maintained worm farm doubles every two to three months.

You can also add compost worms to standard compost bins or heaps, as long as you do not let the contents of the bin get too hot.  Adding them to the right type of compost bin can ensure you avoid rats or mice that may be attracted to an open compost heap.  Even in a standard open worm farm you should cover the food scraps with some soil to avoid attracting vinegar flies or other animals. 

You can either buy commercially available worm farms or you can have a go at building your own.  This can be a fun activity for you and the kids.  Kids really love interacting with and understanding their worm farm.

To build a worm farm you should choose a shady spot outdoors, preferably with good drainage. To avoid invasion by grass or tree roots that might be close by, place the worm farm on a plastic sheet.  Once you have your spot you should line your container with a few sheets of dampened newspaper.  Your container can be something more substantial like a wood sleeper planter box or something more modest like plastic containers or polystyrene boxes, but it must have a solid base and then different levels for the worms to migrate through.  Again you can simply purchase a commercially available farm at most garden and hardware stores.

Half fill the container with bedding mix that is moist and you can use old compost or shredded paper for this purpose. You want to make sure your bedding mix is less attractive or fresh than the food scraps that you add so the worms keep eating your scraps.  Even grass clippings can be a good bedding material.

Depending on the sort of container you are using you need to make sure there is adequate drainage.  Worm wee is a fantastic fertilizer and many of the schools I work with actually collect this from their school worm farms and sell it at local markets.  Once you’ve got this all set up and arranged adequate drainage you’re ready for the fun par, adding the worms! You can purchase your initial population of worms from many different outlets, but just make sure they are actually compost worms. 

Once you’ve added the worms you can cover them with a layer of compost, soil or hessian and add some water to make it moist, but not soggy.  If you worm farm dries out completely your worms will die, but it is important not to over water them because there is good moisture in the food scraps you add each week.

You worm farm is just about complete except for the glorious food scraps that used to be waste.  You are now ready to start adding fruit and vegetable scraps. You can do these weekly by keeping a small compost bin in the house or on an as needs basis.  You should start off with small amounts of food and the way to check if you are overfeeding them is keeping an eye out for any uneaten food from week to week. 

Interestingly your worm population will grow in relation to how much food you feed them and the size of your worm farm.  Remember a worm farm can be really small for a small household or huge for industrial operations.  After time you may need to add more levels to your worm farm or start another farm altogether as the population grows or you start generating more food scraps.

For more information on how to make a worm farm you can go to http://www.abc.net.au/creaturefeatures/make/wormfarm.htm or http://yourenergysavings.gov.au/waste/reducing-recycling/kitchen-food-waste/start-worm-farm