What is worm farming?

Tiger worms love the darkness and moisture of a worm bin.

Worm farming is also known as vermicomposting, vermiculture, worm farms, worm bins or a wormery. It is a self-contained composting system that doesn’t generate heat, and retains most nutrients for reuse. This system is not able to take garden waste and some types of food waste, but they are compact and moveable, which makes them great for people who have limited space. Properly maintained, it is an odourless system and worm castings (manure) make excellent compost.

The worms, usually Tiger Worms, are exactly the same as those in a compost bin or heap, but are contained in a smaller transportable bin that can be indoors, outdoors, on a porch or verandah.

Tiger Worms are not the same as the earthworms found in garden soil. Tiger Worms will not survive in the garden and need the dark and moistness of a worm bin or compost bin to live.

Worm farming

Why worms?

Simple, natural and fun!

The worms eat your kitchen food scraps and process them into castings. This reduces the rubbish you put out at your gate and makes an excellent soil conditioner.

• Worm tea is the liquid waste the worms produce. This is also an effective fertiliser.
• It’s a great system for people with limited space.
• It’s an easy and fun way for people of all ages to recycle kitchen waste.

Worms live to eat!

Getting started

Anyone can start a worm bin. All you need is a suitable container, bedding material, and of course, worms.

Where to buy your worms

You can buy worm bins from The Warehouse (all stores), Payless Plastics, Mitre 10 stores and some hardware retail outlets. Check online at sites such as Trade Me: www.trademe.co.nz.

Worms are available from:

CBEC Eco Solutions, Whāngārei
Phone: 09 438 8710
Email: ecosolutions@cbec.co.nz

Earth Angel
Earth Angel can provide worm bin and worms and courier direct to your door.
Phone: 09 834 0699
Email: michelle.dawson@xtra.co.nz
Web: www.earthangel.co.nz

Kiwi Earth Worms
P O Box 13
Matakana
New Zealand
Phone: 09 422 9082
Web: http://www.kiwiearthworms.co.nz

Tiger Worms
To purchase Tiger worms for your worm farm, you can contact:
Jocelyn Allen
Ph: 09 4355 057

Worms are also available through certain stores and via mail order. Try an internet
search, Trade Me or the Yellow Pages.

A home for your worms

Making a worm bin

Worm bin.

You can recycle or make a suitable container from wood, plastic or metal. Old tyres or baths make great worm bins too. The container should ideally be 20-40cm deep with a relatively large surface area (about 40 x 40-60cm) because worms like to work near the surface.

Worms need air to live, so put a few holes in the bottom of the container for aeration and drainage. If the contents get too wet, then drill some more holes.

Bins should be raised up on bricks or blocks to aid air circulation and drainage.

You can place a tray under the bin to capture excess liquid. This makes an excellent plant fertiliser. Use diluted at a rate of one part liquid to 10 parts water.

Setting up your wormery

• Old carpet and canvas are ideal for covering a ground-based worm farm.
• Place moist bedding (shredded paper or similar) in the worm bin, plus one or two handfuls of coarse sand or topsoil.
• Add tiger worms (1000 or so). You can buy these locally or via mail order.
• Alternatively, you can source them yourself as worms live wherever a good supply of organic material is available. Check your friends’ compost bins for worms or a farmer with a mature manure heap and collect the worms. Kids will
  love this!
• Bury kitchen scraps just below the surface of the bedding.
• Cover with sacking or a loose fitting lid that will keep the material from drying out and provide a dark environment for the worms.
• Additional fresh bedding should be added at least every two months.

Harvesting your compost

Harvest the compost (worm castings) after three to four months and feed to your plants.

The easiest method is to use a hand fork to remove the top 150mm layer and set it aside for starting the next bin. The remaining contents can then be removed for either immediate use or stored until required. Put the top layer back into the bin with some fresh bedding to start the process again.

Alternatively, tip the entire contents of the bin onto a tarpaulin or plastic sheet. Spread the compost to form a layer approximately 100mm thick. The worms dislike light and burrow deeper. Over a period of about an hour, you can remove the compost in layers as they move deeper and you will be left with a mass of worms which can be added back into the worm bin with new bedding.

You may prefer to simply move the finished compost over to one side of the bin, place fresh bedding into the space created and add food waste to the new bedding only. The worms will gradually move over and the compost can be removed.

Worm bin - before and after.

Top up the bin with fresh bedding to replace the compost removed. The worms require bedding in which to live and lay their eggs.

Suitable bedding includes newspaper torn into 25cm wide strips (avoid coloured print), cardboard, peat, straw, aged manure or compost. Sawdust is not recommended as it contains resin and similarly, chicken manure should be avoided as it is too acidic.

It’s as simple as that.

What to feed your worms

• Feed worms left-over food scraps, vegetables and non-citrus fruit peelings, tea and coffee bags, coffee grounds and eggshells.
• Meat, fish and dairy products may be fed in moderation. Make sure you bury them in the bedding (not too deeply) to avoid odours and flies. If odours are a problem, then leave these products out.
• Don’t feed your worms onions, oil, fats or oily foods, citrus peelings or acidic fruit, peppers, or spicy foods.
• Garden waste is generally not suitable for these worms. Materials such as grass clippings heat up quickly, which can kill the worms.
• Garden waste is best dealt with by conventional composting.

Top tips

Put your worm bin in a sheltered, shady area, away from wind and sun.

To prevent odours, slimy conditions and attracting flies, add food regularly rather than in large quantities. Food in excess will sour and rot before the worms can deal with it.

Odours generally occur because the system has been overfed, allowed to become too moist or the bedding has become packed, limiting airflow. It is important to fix this, otherwise the conditions may kill the worms.

Chopping or mincing up food scraps helps speed up the process.

Add crushed eggshells or a light sprinkling of dolomite or garden lime once a month to ensure a good environment for the worms, who don’t like acidic conditions.

Worms need to be kept moist, but not soggy. If they dry out too much they will die; but if things are too wet they will drown.

Be aware, that as worm farming doesn’t generate heat, any seeds included with the food (eg pumpkin or tomato) may still germinate!

Using the worm compost

Finished worm compost is rich in nutrients. It can be used for potted plants or in the garden. Use in small amounts (a handful mixed into the soil when transplanting gives plants a good start).

Compost used as part of a potting mix or as a topdressing around potted or as a topdressing around potted plants should not contain worms.

Acknowledgements
We would like to acknowledge the Auckland Regional Council and Christchurch City Council Waste Management Unit for the use of this information.