Your 101 guide to composting and worm farming
Not composting yet? Experts say composting could be the single most important thing you can do for the planet. Composting food waste not only diverts your food scraps away from landfill, where it would otherwise be releasing methane gas into the atmosphere and liquid leachate into creeks and streams, but it also creates healthy soil for growing food teeming with nutrients and connects you back to the Earth.
As we’ll see, composting and worm farming are all about health, and it’s a lot easier than you’d think.
Peter Rutherford is the senior ecologist at Kimbriki Eco House and Garden, a sustainability learning centre in Sydney. According to Rutherford, who has been running workshops on composting, worm farming and organic vegie gardening for 18 years, “The soil is a living creature; everything comes from it. A knowing of ourselves can be deepened through this incredible life in the healthy soil and there are billions of microscopic organisms in every handful. I feel it — something deeper is happening when I interact with soil.”
That’s a statement based on more than just instinct: research published in the journal Neuroscience in 2007 on this process indicates that microbes in the soil can actually make you happy. “Mycobacterium vaccae [from soil] has been shown to boost the levels of serotonin in humans,” Rutherford explains. “We breathe them in when we hold, dig or simply smell the living soil.”
“Mycobacterium vaccae [from soil] has been shown to boost the levels of serotonin in humans. ... We breathe them in when we hold, dig or simply smell the living soil.”
The ecologist encourages children to get back to nature. “It is so important to their immune systems to be exposed to dirt,” he says. “Thousands of kids come through here and many won’t even touch an earthworm. We get them interacting with the natural world; it’s a health issue.” That’s a point echoed by Gardening Australia host Costa Georgiadis, who describes soil as the most life-giving element we have; it’s what keeps us alive.
It’s also a view held by Graeme Sait, founder and principal soil scientist of the sustainable agriculture training body, Nutri-Tech Solutions (nutri-tech.com.au). He notes the alarming ratios of degenerative diseases linked to nutrition and believes a loss of humus in soil is a primary factor. Humus is the stabilising “soil glue” and storage system for carbon, water and minerals. It improves the nutritional value of food and cleanses soil of contaminates, preventing nitrate leaching.
Humus holds all the trace minerals that are principal drivers of plant immunity, says Sait, and improves the nutritional value of food. Without humus, soil can’t hold a range of minerals. Yet, according to Sait, we’ve already lost two-thirds of humus in our soils, which means a loss of nutrient density in food.
Composting adds humus to the soil and, by doing that, adds more mineral delivery to you. Composting is vital because it stabilises carbon and promotes the production of more humus through biostimulation and inoculation. By composting, Sait says, “You’ve introduced an inoculum of cellulose-digesting, humus-building organisms back into your soil.”
“Whatever you can compost in your own yard is more profound than turning off your lights or putting on a solar panel, in terms of your personal contribution [to the planet].”
Regenerating humus is a significant benefit of composting, but not the only one. Composting holds the potential to greatly reduce methane gas emissions. With the typical household filling over 40–50 per cent of their general waste bin with food waste, landfill creates massive methane sinks. Methane is a colourless, odourless, flammable gas formed during anaerobic plant decay or released as a byproduct of ruminant (sheep, cattle) digestion. Sait says there is no greater contribution you can make to averting climate change than composting. “Whatever you can compost in your own yard is more profound than turning off your lights or putting on a solar panel, in terms of your personal contribution [to the planet].”
Councils are so keen to get your excess food out of landfill and into compost that most run free composting and worm-farming workshops regularly. These informative workshops give you the confidence to get going and the motivation to keep you composting if you’ve paused.
An exciting new development at Kimbriki began in late 2016 when Kimbriki, owned by Northern Beaches Council and Mosman Council, started a tender process seeking submissions to develop a new resource recovery facility on site. The intention is to develop a long-term, alternate waste-treatment technology for all household food waste in NSW’s Northern Beaches and Mosman residences.
Even if your council is already composting kitchen waste, such as it is in Penrith, Northern Rivers and the Municipality of Kiama, composting at Home rejuvenates the soil in your own backyard. Sait calls it “minding your patch”.
Peter Rutherford invented a powerful principle for healthy compost called A.D.A.M, now taught in many council-run workshops today. When composting, keep the below in mind:
- Encourage an abundance of life such as healthy microbes, worms and little creatures into the compost to act like worker bees.
- Add a variety of different ingredients to your compost.
- Use a spiral mixing tool regularly and mix the compost to give it air.
- Water your compost with buckets of water gathered in the shower, from excess washing when cooking rice or activating nuts, and from half-cups of undrunk tea, coffee, etc. Squeeze a ball of compost in your hand to check moisture levels: it should be neither dry nor dripping. Add more water accordingly.
How do you go about composting? Start with one compost bin, gradually increasing to more. Typically, the compost in the first bin is ready to be used once the second bin is full. You can then start operating a third compost bin so you’re always composting, without having to rest the process.
The castings, which will be in the home tray, are composed of highly concentrated humus. The worm juice, diluted with water as a tea, can enrich the quality of the soil in your garden.
Position the compost bins in sun or shade, in an area with good drainage. If you’re worried about vermin such as rabbits or mice, try digging the compost bins about 10cm into the ground as a deterrent, as they do at The Eco-Garden at Sydney’s Fagan Park, or put chicken wire around the base. Aerating your compost weekly discourages vermin.
Composting is a mixing process. The green inputs (nitrogen) include kitchen organics like fruit and veg peelings, green garden organics like grass clippings and weeds, and manure. The brown inputs (carbon) include dry leaves, twigs, woody mulch, paper and straw. Only add meat and dairy once you’ve got the hang of things. Mix your heap at least once per week or more often if you have time. Use the amazing spiral mixing tool: an aerating device with a curly end that helps you move your compost around and makes it easier to pick it up.
Filling your compost bin
Start with a brown layer and water well. Sprinkle on dolomite lime, then add two shovelfuls of rich compost, such as what you can buy from Kimbriki or other similar centres (or beg from a friend). Add manure.
Next, add a green layer such as lawn clippings and prunings, then add water. Add another brown layer and wet down. Aerate using the spiral mixing tool to start the heating phases. Cover with hessian sacks so it can breathe, and put the lid on. Each time you add to the compost bin, take the lid and sack off, aerate with the spiral tool, add a green layer, then brown layer in equal parts, sprinkle lime and manure on each layer, add water, then place the hessian bag over before putting the lid back on.
Adding dolomite once a week will balance the pH, and Sait suggests to add clay-based soil as well in order for the mycorrhizal fungi to create humus that lasts for 35 years (instead of only six months).
When the bin is full, keep mixing it each week, adding dolomite and manure weekly, and allow it to mature for 6–8 weeks before using on your Garden. Continue composting into the next bin.
Ready for use
Your compost is ready when it’s light and fluffy, smells earthy, is dark in colour and you can’t see any traces of food scraps any more. Add this black humus, full of microbes and nutrients, to the drip line of plants. The drip line is where the furthest leaves drip dew, and is where the most active roots of plants are. Spread the compost around the ring of the drip line of the tree, add lucerne hay to cover and water it in. Also use a few handfuls of your mature compost with every vegie seedling you plant.
Got a problem?
Many composting problems can be solved by aerating with the spiral tool and adding dolomite. If it smells, add more of the brown ingredients. If it isn’t heating up, add more water and more of the green ingredients. Make sure you wet down your compost bin on hot days or before you go away. Call the Waste Management Team at your local council for further advice.
Worm farms are an incredible system that produces pure humus. If you don’t have a backyard, worm farming and balcony growing are perfect, and it can also be used in addition to compost bins.
The types of worms used are red or tiger worms. Buy them from a reputable source such as your council or ask a friend with a thriving worm farm for a handful to start your own. Castings (worm poo) can be fed to house plants, seedlings, potting soils and used on top dressing. Use the ADAM principle (see the box above?) and don’t overfeed the worms. Worms are hermaphrodites and self-reproduce, having their own population control. They will eat their own bodyweight in food. For more worms, make their food sources easier to eat by blending or chopping the vegies. Worms love the goodness of leftover green smoothies!
Position your worm farm out of the sun and keep it well hydrated. Worms can conveniently live indoors, such as in the garage, provided they receive plenty of food and water.
No place like home
Worm farms are a three-tray system. Consider the worm farm a home. The bottom tray is the bathroom, catching water, so keep the tap open or remove it altogether and place a bucket underneath it to catch the worm juice. Place your worm farm on a slight angle to encourage the liquid into the bucket, and remove the feet, replacing them with bricks as the worm farm will get heavy. The middle tray is the bedroom or home tray, and the top tray is the dining room or feeding tray. Use soil or mature compost in the home tray for set-up and place all your scraps in the top feeding tray.
Worms come up through the holes to feed, then live in the home tray, so make sure the tray is full enough for worms to climb up to the top tray. Always place a hessian bag over the surface of the top tray before putting the lid on. Worms love to eat the bag, so you’ll need more than a couple as time goes on. Ask your local cafe for hessian from their coffee bags.
The worms will aerate the farm for you. The castings, which will be in the home tray, are composed of highly concentrated humus. The worm juice, diluted with water as a tea, can enrich the quality of the soil in your garden. Diluted, worm tea can be used as a spray on plant leaves and directly on plants and vegies, watering into the drip line. Castings are full of beneficial bacteria and enzymes and help balance the pH of your soil.
When you feed the worms, always add some soil on top, too, then mix and fluff up the feed tray with a small hand fork. Flood the worm farm once a week with an entire bucket full of water to keep everything moist and, on very hot summer days, flood again. Sprinkle dolomite onto the feeding tray once a week after watering, making sure it doesn’t touch the worms as it will burn them. Add basalt rock dust to the worm farm to add minerals to the system that will ultimately benefit your growing food.
When your worm farm is full, it’s time to change trays and use the castings. To do so, follow these steps:
- Take off the hessian “worm blanket” (it may be time for a new one).
- Lift off the full, top feeding tray and carefully put it to one side.
- Lift off the home tray. Empty the contents and clean the tray. The beautiful black worm-casting material can either be used in small amounts on your potted plants or around the drip line of plants in your garden. Make sure you always cover it with mulch. You can also mix the castings with maturing compost.
- Rinse out the bottom liquid collection tray.
- Lower the full feeding tray into position as the new home tray.
- Put the clean empty tray on top, add a couple of handfuls of soil into it and begin feeding.
This rotation method is repeated every time your feeding tray fills up (usually around 2–3 months, depending on the number of worms and how much you’re feeding them).
Enjoy this wonderful, composting science! It’s vital for your health and the health of the planet that you do.
What else can you do?
If you’re looking for further ways to care for your health from the ground up, Graeme Sait offers these suggestions:
- Buy good-quality, organic compost.
- Buy food from those practising regenerative farming.
- Eat fresh foods with the deepest, most intense colours of the rainbow.
- Produce your own food and get into permaculture.
- Plant succulents and moringa trees. Crassulacean acid metabolism (CAM) plants are carbon building and easy to propagate. Sait says the moringa tree is one of the most nutrient-dense food plants on the planet.
- Never work-over wet soil because you will magnify the humus-losing phenomenon four-fold.
- Never use nitrogen without combining it with a carbon source such as compost or molasses.
- Bring back earthworms into the garden. They increase the infiltration and water-holding capacity of your soil and incubate valuable bacteria.
- Use science, ie “adherence to natural laws and principles”, in your composting technique.
- Lobby councils to have separate, uncontaminated collections of organic matter; for payment for carbon credits to primary producers for increasing humus in soil; and for legislation to protect mycorrhizal fungi — the most important microbe we have — from herbicides by demanding glyphosate be banned.
For more great garden ideas, why not check out our Wellbeing Directory
Like what you read?
Sign up for a weekly dose of wellness
Tropical ecosystems face imminent collapse
Global biodiversity set to collapse unless concerted action is taken to reverse damage to the tropical ecosystem.
New tool to calculate nitrogen footprint
Australian researchers develop a tool to calculate the nitrogen footprint of an organisation.
Sustainable beer that tastes like beer but without hops
Genes from mint and basil engineered to produce yeast brews “hoppier” beer than that made from traditional yeast and hops.
Organic food in plant-based diet benefits our environment
A plant-based diet, particularly organic food consumption is better for the environment than an animal based one.