Making use of the earthworm
Earth worms
Imagine a miniature composting machine that stays on the job 24 hours a day, 7 days a week, does not create any smell and leaves you with a wonderful free package of solid and liquid fertiliser that your garden will thrive on. The only fuel this composting machine needs is a variety of organic materials that some people consider as waste. I am talking about the humble earthworm.
By understanding the role that earthworms play in their natural environment we can work out ways that we can adapt them to living and working in the garden environment. Earthworms are found in natural ecosystems all over the world with thousands of different species having adapted to all kinds of soil and climatic conditions. Earthworms feed on decaying organic matter such as the leaf litter on the surface of the soil in a forest. They digest that organic material and then burrow back into the topsoil where their excretions recycle that organic material in a way that adds nutrients and humus that helps to create and maintain a healthy, vibrant soil environment that is very plant friendly.
We can take advantage of earthworm activity in the garden by helping them to breed up in the soil. There are a couple of simple ways to do this. The first is to bury your kitchen scraps in shallow holes in your garden soil and then burying them. Any earthworms in your soil will come and feed on this material and will increase in number. Alternate your holes around the garden for maximum benefit. Another way of encouraging worms is to put a 2-5cm layer of manure underneath mulches that you may be applying around trees and shrubs. The worms will feed and breed in the manure and cultivate the topsoil in the process.
Worm farms are another way of harness the beneficial properties of earthworms. You can easily construct your own worm farm with re-used material such as polystyrene boxes with numerous holes punched in the bottom. Alternatively there are commercially available worm farms with a series of trays stacked one on top of another that the worms can move freely between. When all the trays are full the bottom one (which has had longest to break down) is emptied and rotated to the top to be refilled. This way the system can go on indefinitely and is generally big enough to accommodate all the kitchen scraps generated by an ordinary household.
Worm farms are simply an intensive form of composting that requires a special type of worm that can thrive in concentrated amounts of organic materials such as kitchen scraps. The two most commonly available species of worms for this purpose are red and tiger worms.
Worm farms are designed to maximise the activity and population of worms to achieve a high turnover of organic material. Essentially a worm farm could be considered as a very intensive form of cold composting that is also very suitable for receiving small amounts of new material every day if required.
Key points to operating your own worm farm
The keys to operating your worm farm successfully are as follows:
- Keep it out of direct sunlight as the worms can cook on a hot summer day,
- Feed your worms a varied diet. Do not just use kitchen scraps as these end up becoming too moist and literally drowning your worms. Use materials such as shredded paper, aged sawdust or chopped up dead leaves to mix with moist materials so your worms can breath,
- Do not put meat in the worm farm as it will attract vermin such as mice. Use rodent traps if mice or rats start visiting your worm farm,
- The worm ‘juice’ that drains from the bottom of your worm farm should be collected and used as a liquid feed for your plants. Be very careful to dilute to the colour of weak tea as it is very strong when derived straight from your worm farm
- The castings that result from your worm farm are also a rich fertiliser that is best used in vegie gardens where it can be dug into the soil to re-invigorate it between plantings.
More about worms
Common problems with worm farms & compost
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