The main work worms do in your garden is tilling and aerating the soil. They burrow very deep, leaving channels through the soil that break up clods and allow air to enter and water to penetrate and drain away.

In the process of eating at the surface and eliminating lower down, they introduce organic matter to the deeper levels and steadily increase the depth of topsoil. Their main role is to digest decomposing organic matter, converting it quickly into a form plants can use as nutrients.

It is important to maintain good soil structure when gardening organically. Unlike mechanical tillers, earthworms do not damage the soil by inverting it, creating hardpans or breaking up the crumb structure. They never have mechanical breakdowns, they do not create noise or pollution, and they use garbage for fuel - an excellent way to dispose of your kitchen scraps, especially if you live in an apartment.

DIY Worm Farming
Commercial worm farms are very practical, widely available, easy to use and are quite aesthetically pleasing. You usually buy them with a small supply of worms to get you started. Choose either Red Worms or Tiger Worms. However, if you already have a suitable 'home' for your worms you don't need to spend the extra money.

A pair of old concrete laundry tubs in a shady spot near your kitchen door or close to your propagating area (or both) is ideal. Have the tubs elevated to make collection of the fertilizer easy. Leave the plugs out and put a strainer in the hole so that any excess water can drain.

Fill the first tub with compost and mix in a handful of dolomite or agricultural lime, along with about a half a bucket of soil. Place a bucket under the plug-hole and water this mix with a fine spray until it is quite saturated and starting to drip into your bucket.

Tip in your starter population of worms and cover the surface with an old hessian sack, wet cardboard, old carpet or similar. Worms usually live underground so they thrive in an environment that is cool, dark and moist. You can purchase a tub of 500 - 1000 worms to get started. They are available from professional worm breeders and can be sent through the mail. Many garden supply centres will also have them.

A close-fitting solid lid on your farm will suffocate your worms, so you need to fit a fly-mesh or shade-cloth screened lid to keep out flies and other insects.

For the first month you need do nothing except make sure the farm is kept quite moist, but not awash. Once the farm is settled in you should not need to add extra water. If your farm is exposed to rain, make sure the plug is left out or your worms will drown.

The compost itself will feed the worms for quite a long time, but to get maximum breeding it is best to add some supplementary feed every few days, especially as the population starts to increase. Add a dessert-spoon-full of lime or dolomite to each kilo of food.

You can vary their feed by rotating between:
- a bucket half-filled with water and cow or horse manure, mixed to a slop and poured over the surface;
- a blender filled with household scraps(not citrus or onion peel or meat) blended to a slop and poured over the surface;
- rotten potatoes, pumpkin or fruit, just placed on the surface;
- half a bucketful of new compost, spread over the surface.

Worms also like:
• soaked and ripped pizza boxes
• shredded and soaked cardboard, paper
• leaves, dirt, hair, egg shells

Worms do not have teeth, so scraps should be cut into small pieces - waste from a vegetable juicer is ideal.

Plants from the onion family (including garlic, leeks and shallots) and citrus fruits contain volatile oils. If any of these are included in the food scraps the worms will climb out of their housing to get away from the smell.

Within a few months the tub should be filled with a writhing mass of worms, and it's time to colonise the second tub.

Half-fill the second tub with the same mixture of compost, lime and soil. Put a strainer in the plug-hole and water the mixture until saturated.

Burrow down to the plug-hole in the first tub and put in the plug. Set a hose to just dribbling into the first tub until it is half-full, being VERY careful not to forget it and fill it right up. Leave the hessian on top to exclude light. The worms in your first tub will all migrate into the top half to avoid drowning.
Scoop them out and, reserving some to put in the garden, transfer them to the second tub. Let the plug out of the first tub and drain into a bucket. You are left with a bucket full of very, very rich liquid fertilizer and a tub half full of worm castings.

From now on you should be able to repeat this process every month or so, transferring about a third of the worms out into your garden or feeding them to the chooks each time. This will also ensure that you always have a supply of excellent liquid fertilizer available as well as the rich worm castings. Your plants will thrive!