Recycle organic waste
Nutrient recycling is the foundation of life. Today's organic waste is tomorrow's lunch, so look after those worms and compost piles.
Much of the journey toward sustainability involves us learning how to replenish nature as effectively as we have plundered her. Hence, establishing and maintaining the "food waste to compost to soil to food to food waste" cycle is both an efficient practice and a glimpse of the cycles we must learn to respect all around us.
How to do it now!
If none of your organic material is to go to landfill you'll need to get into composting or worm farming.
With the right preparation, keeping and maintaining a compost bin or worm farm can be quite simple and rewarding! They’re available from most hardware stores. Children love them – and so will your garden.
In addition, many local councils provide discounted worm farm kits and/or compost bins with instructions to ensure they work well. They are generally simple, clean and easy to use.
Worm farming is a method of composting or breaking organic matter down into a form easily accessible to plants through the aid of worms. Worms munch their way through all your food scraps and other organic materials and as a result of their digestive processes they produce castings (worm poo). Casting are easily absorbed by plants and don’t require any further action by microbes once placed on to your soil. They are quickly taken up by your hungry plants.
Worm farming is a relatively simple form of composting as you rely on worms to do nearly all the work. You provide the right conditions (appropriate shelter, moisture and food) and they do the rest.
So what are the right conditions?
Shelter. Worms need a home. Usually this comes with your worm kit, and consists of a single or triple layer of black plastic tubs in which the worms will live. You can use polystyrene boxes or other containers but whatever you use, it will need to have drainage holes to collect the liquid that the worms produce. You can simply place another polystyrene box (or anything that fits well) under the first one, and use this to capture it. Make sure there are no drainage holes in the bottom box or your precious worm tea will drain away. A cover or lid is necessary to protect worms from light, predators and to keep the farm at a stable temperature. Hessian or newspaper is fine to use, but make sure there is not too much light getting in and replace when thinning. If you are using a hard lid, ensure that there are some air holes in it.
Worms don’t like the light - they do live in the earth - so it is important to position their home in a shady sheltered spot. They also like moisture, as they absorb oxygen through their skin from moist soil. Damp rather than wet conditions are advisable as they can drown if there is too much water. With lots of fruit and vegetable scraps you should find that the moisture content is okay in your worm farm. An occasional light spray with water is advisable if it starts to look dry, or after adding dry organic matter such as dust.
When you first start your farm, it is important to lay down some bedding material. Some layers of shredded moist newspaper, followed by some partially broken down pea straw, compost, or even some soil from the garden is fine. Ensure the whole bed is damp. Your home kit should come with its own bedding (e.g. coir).
Then you can add your worms. Most places recommend a minimum of 250 grams of compost worms (around 1,000). And you can’t just take the good old garden variety as they have different requirements. Earth worms like to nestle down in a dark earthy tunnel, whereas compost worms move more freely and will readily slide about in search of food. The three main types of compost worms are Tiger, Indian Blue and Red Wriggler.
Food. It is important not to over-feed the worms while they settle into their new home. A recommended amount is about two centimetres worth of food spread over half the container- or 250 grams per 1,000 worms. You can build up to adding much more material once the worms are established (usually after a week or two). Worms will eat about their body weight in a day.
Regular amounts of organic matter can then be fed to your worms in the form of the following:
- Food scraps including all fruit and vegetable scraps and peelings except for onions and citrus (although small amounts are probably okay).
- Coffee and tea grounds and/or bags.
- Vacuum dust and ash (small applications only).
- Paper, and any unwaxed cardboard, but break it up first.
- Plant clippings and grass - although you should wet the grass as it can be very drying.
- Meat and dairy products attract vermin so are best avoided.
The smaller the material the better. Worms don’t actually have teeth, they suck up their food, so small bits are best.
Unlike a compost heap you don’t need to turn your worm castings. In fact you might do some damage to young worms, so it's best to leave the farm alone, except for adding food and checking on the conditions.
When are the castings ready?
Worm tea, that beautiful rich liquid worms produce should be ready on a weekly basis so regularly check your bottom box (or open the tap if you have a commercial kit) to collect the liquid. This will be too strong to apply directly on to your plants, so dilute it down to the colour of weak tea, and then apply to plants. Once diluted it should be fine to use on all your plants. It's also great on the fruit and vegie patch too.
Castings should take a bit longer to produce and be ready after a month, depending on how well you broke down the supplied material. When you can see lots of rich dark loamy looking material, you are probably looking at some lovely worm castings. If you have a layered system, it is a good idea to put another box on top (with the same conditions as the previous one) and commence putting food in this top box, instead of the previous one. The worms will migrate to their new home through the drainage holes. In about a week or two you should be able to take the box of castings (the middle layer) away and apply it directly to your garden bed. Most, if not all the worms should have also departed, so you can continue the process again with the new top box. Just check for any stragglers and put them with the rest of the worms.
If you don’t have a layered system, you can move your box to a sunny area or add a light source and watch the worms quickly depart to the bottom of the box. You should then be able to scoop out the top layer of castings for your garden. As you scoop it out, check for any worms and return to the remaining castings. You can do this a couple of times to maximise the castings you get.
Worm farms are a simple and effective way to recycle organic waste and feed your garden.
Online worm farm specialists. Try the following online shop for your worm farming kit and more information on worm farming.
The Bokashi Bucket is another great option for small urban spaces. The Bokashi Bucket ferments layers of chopped kitchen waste overlain with Bokashi mix, a Japanese discovery made up of grains or saw dust with Effective Micro-organisms (EM) to speed up the fermentation process. The bucket is sealed air tight, so there’s no access for bugs or vermin, allowing your meat scraps to be included also! There’s also no worms to care for, so onions and citrus are back on the composting menu.
Even better, the air tight seal means no nasties can get in or out of your Bokashi Bucket, thus no smells (or very little smell, mostly just the nice earthy smell of the Bokashi mix). This means you can even keep your Bokashi Bucket in the kitchen cupboard!
Where to get it. Bokashi Buckets are available at most hardware stores and nurseries. The buckets are most often made of recycled plastic, with a grate at the bottom to allow the juice to collect beneath your scraps, and a tap to release the juice.
How it works. Collect your daily organic scraps in a recycled plastic container on the kitchen bench and add them to your Bokashi Bucket in layers. As you add layers, squash the scraps into the bucket with a potato masher and sprinkle on the Bokashi mix to cover lightly. Your bucket will yield lovely ‘bokashi juice’ every few days depending on how much you feed it. Dilute the juice 1:100 for use on the garden or use straight down sinks or toilets to clean drains. Once your bucket is full, bury the fermented organics 20-25cm below the surface of the soil and it will become lovely compost.
No digging space? Bury in a friend’s garden, their soil will love it!
The Bokashi Bucket is also a great option for Fly In Fly Out workers or those away from home quite often. With the bucket’s air tight seal in tact you can leave it for several weeks without worrying your compost will go rancid.
What is compost and how do you do it?
Compost is the process of decomposing organic matter through the action of microbes, bacteria and fungi. By providing them with the right conditions these organisms can rapidly break down your organic matter into sweet-smelling crumbly compost or soil.
Compost has many benefits for the garden:
- it provides nutrients to the soil
- retains moisture and enhances the water holding capacity of the soil
- improves drainage (in clay soils)
Other environmental benefits include:
- assists with the absorption of carbon from the atmosphere
- recycles organic waste on site
- reduces pressure on landfill sites and associated problems
Composting is an ever-present cycle recurring in nature where leaves or animals fall and die. Their bodies are then broken down by small creatures (invertebrates, bacteria and fungi) that effectively eat up the remains of the creature and release the nutrients from the dead organism back into the soil, and so the life cycle continues. Simple really. The aim of your home compost heap is to mimic this process, only quicker.
There are a few rules about composting.
Site selection. Select a warm and sunny spot in your garden (but protected from the harsh western sun with shade cloth or hessian). It is always best to compost on soil, as this allows easy access for worms and provides a good base for drainage.
Container type. You can choose a container, such as a commercially bought compost bin, or tumbler or build a heap. Most heaps are contained within wooden palings built like a 1 metre square box, only without a front or a lid or you can have a pile on its own. This site focuses on the compost heap.
Food. Your compost eats kitchen and garden scraps. Generally it requires a mix of 1 part nitrogen and 20 parts carbon. As a general rule nitrogen is the green leafy matter and manure while carbon is the brown dried fallen leaves, woody and paper-based materials.
Examples of nitrogen matter
- lawn clippings
- garden weeds
- fruits and vegetable peelings and scraps
- tea and coffee grounds
- yarrow, comfrey and dandelion (compost activators)
- pea straw, lucerne
- horse, cow and poultry manure
Examples of carbon matter
- dry leaves,
- twiggy prunings
- sawdust (high carbon content)
- pine needles
- vacuum dust
Compost activators. Some plants are really good at speeding up the composting process, and it is worthwhile growing some of these nearby your compost heap so that you can throw them in from time to time. (Many are also great companion plants and will also assist the growth of neighbouring plants). Three favourites are comfrey, yarrow and dandelion (yes a common weed, with excellent medicinal and composting properties).
Blood and bone, and manure are other compost activators providing heat to the heap.
Air. Turning your compost pile regularly provides air for the organisms and helps them to work efficiently. It also generates heat which encourages further organism activity. If you are using an anaerobic bin this step is not necessary, although an occasional turn wouldn't hurt. What’s more, drilling small holes in your container is another way to increase air circulation, lessening the anaerobic decomposition.
Moisture. Bacteria and other small organisms flourish in moist conditions, so it is important that your compost heap is damp. As much of the vegetable and fruit scraps are composed of water, this will help keep the pile moist, but if it looks as if it is drying out, or you see any signs of ants, give it additional water. Remember that too much water is a problem, too. Damp, but not wet, is the key.
Heat. When the compost heap has the right mix of ingredients including some moisture, lots of air, and a good balance between carbon and nitrogen matter then the temperature can get quite hot. Bacteria and micro organisms can feed at very high temperatures (up to 60 degrees) and also generate heat through the decomposition process.
Putting it all together: layer upon layer. The best way to start a compost heap is with a selection of food materials that you have been collecting. The chart below is an example only, it is not a rigid plan but gives you an idea of how to alternate the layers of carbon and nitrogen. When starting a heap it is advisable to include layers of manures and other compost activators to really get it going.
For a heap/ open container
Try the following process to get your compost heap going:
- Start with a layer of twigs or pruning to provide some air circulation at the base of your heap (carbon).
- Follow with a layer of nitrogenous material such as green leafy material and a scattering of manure (nitrogen).
- Dry leaves, or twiggy cuttings (carbon).
- Green leafy material (garden or kitchen scraps) and more animal manure (nitrogen)
- Straw or dried leaves (carbon).
- Yarrow, comfrey and dandelions (nitrogen).
Repeat this process with alternate layers of nitrogen and carbon, remembering that you should have a 1:20 ratio of nitrogen to carbon.
Regular maintenance of your heap
- Check to see the heap is moist enough. If you are concerned, add some water.
- Finish with a pile of straw, old newspapers, or hessian.
- Regularly turn your compost heap - at least once a week to ensure there is adequate air.
When regularly turned, a heap will take approximately three months to break down. The process will be slower if you continue adding material.
Tips for improved composting
- A shredder, either a mechanical one or an old-fashioned chaff cutter, can be a useful implement for reducing the size of the particles and therefore speeding up the decomposition process.
- Include compost activators in with your nitrogen layers. These will speed up the process of decomposition.
- Other quality compost ingredients which will add vital nutrients to the final product include chamomile, chickweed, melons, sow thistle, stinging nettle, tansy and valerian.
Using it on your garden
Compost is a rich type of soil that can be dug lightly into your garden or placed directly on the surface of beds. If laid on the surface it will act as a mulch before being decomposed further. Unlike worm castings, compost still requires further work by soil organisms to break it down in a usable form by plants. In winter this process can be quite slow and making some compost tea out of your compost may be a preferable solution particularly for your vegetable patch.
It is also advisable to note that some natives particularly the proteacea family (grevillea, banksias and hakeas) don’t like high levels of phosphorus and while this may be relatively low in your compost, it is worthwhile avoiding the use of compost around these plants. However. it is fine near other natives and in native gardens with sandy soils as it will assist with water retention and the stability of the soil structure.
- For more help, download the Composting Easy Guide (PDF) from the 'It's a Living Thing' website.
Why is this action important?
Humans consume an ever-growing proportion of the organic material produced on this planet. For this to continue perpetually we need to ensure that we are efficiently recycling the nutrients (organic waste) back to the soil, where the food is produced. Recycling organic waste into compost or worm castings keeps those organic elements in nature and available to grow food and feed nature in the future.