Reducing our waste

What is compost/composting?

Composting is the process of organic materials breaking down into nutrient-rich soil. Compost can be made from organic waste such as food scraps, garden waste, paper and cardboard, and animal manure. It re-uses the nutrients from the organic waste and can be used on gardens and vegetable gardens to feed the soil and fertilise plants.

Composting is easy to do a simple compost bin or pile at home, at community gardens, or bigger volumes are done in large-scale commercial composting facilities.

Why is composting important for the health of the environment?

Organic materials break down in landfills to create methane that contributes to the climate crisis. Composting your organic waste prevents methane release into the atmosphere, while turning organic carbon into soil, reducing the impact of waste on the environment and helping to slow the effects of global warming.

How do I start composting at home?

You’ll need:

• A compost bin, or a large untreated wooden box, or small area where you can start a compost pile (on grass or dirt is best)
• Brown sticks or ferns
• A garden fork, pitchfork or compost aerator
• An indoor scraps bin or container with a lid

Getting started:

Set up your composting container in shaded area outside, that is easily accessible. Place brown sticks or ferns in the bottom of the compost bin or pile. This helps to create air flow so your compost can break down faster.

1. Add brown items such as leaves, and shredded paper or cardboard.
2. In a separate scraps bin or container with a lid, collect any organic food scraps such as fruit or vegetable skins, peelings, or left overs (referred to as your green materials).
3. At the end of the day or when your scraps bin is full, empty it into the compost outside. You could also add fresh lawn clippings when you mow the lawn.
4. Add in any brown leaves, tissues, paper towels, shredded paper or cardboard (otherwise called your brown materials), on top of the organic scraps or lawn clippings, and continue to create green and brown layers like a lasagna. Avoid adding dairy and meat unless you aerate your compost regularly, to prevent bad odour.
5. To speed up the composting process, turn the compost with a garden fork, pitchfork or compost aerator. Otherwise, you can leave the compost to break down on its own.

Your compost is ready to be used on your garden when it is dark and crumbly, like soil.

Is composting easy?

Composting is a simple, low-maintenance and effective way to reduce your waste output and environmental footprint.

The great thing about composting is that the more time and effort you put into it, the faster your organic waste will break down, be ready to use, and you’ll make better quality compost. But, even if you don’t put any effort into maintaining your compost it will break down on its own over time.

If you are time-poor, you may prefer a low maintenance style of composting. If you have more spare time available, you could maintain a more efficient compost that breaks down your waste faster. This means you can choose a type of composting that suits your lifestyle.

What items can be composted?

It is best to only put organic and green waste into your compost. This includes food scraps, garden waste, leaves and foliage, glass clippings, paper and cardboard, and animal manure. Compost will break down faster in smaller pieces, so you could shred or chop the organic items before putting them into your compost pile/bin.

You should avoid composting meat and dairy, as this can create a smell if your compost is not aerated often enough, or does not have enough brown materials in it (such as cardboard, paper, dry leaves etc.). Bones will take a very long time to breakdown in the compost, and are also best buried in the garden or put in the red-lid rubbish bin.

However, if you maintain a ‘hot compost’, you are able to put meat, dairy, weeds and cooked bones into it as they will break down at a much faster rate than in normal compost. Learn more about hot composting below.

What items can’t be composted?

Any items that aren’t made from natural materials, or are chemically-treated, or will take a very long time to break down like uncooked bones. Don’t put in items such as sand or stone.

How do I maintain my compost?

Transforming waste into compost requires aeration. Turning your compost regularly will increase airflow and help it break down faster. If you turn your compost once a week, (depending on what you put into the compost pile) it will be ready to use in about 6 months to a year. Otherwise, you can leave your compost to break down on it own over time.

You can tell when it is ready as it will smell earthy, and will be dark and crumbly, like soil.

To improve air flow in the compost pile, add one part green materials to three parts brown materials. This means you should add 1 part food scraps/animal manure/grass clippings to every 3 parts of dry leaves/paper/cardboard.

Does compost smell?

Compost can smell if it is not aerated enough. The problem occurs when the compost pile is dominated by green materials, such as garden waste, food scraps or animal manure. To fix this, add more brown materials/carbon such as paper, cardboard or dead leaves, or turn your compost more often to aerate it. This will help it to break down more efficiently and reduce odour.

Compost can also smell if there is too much water in it, so put a cover on the heap to stop the rain from getting in.

Putting items such as meat and dairy in your compost can create odour. It is best to bury these items in a hole in your garden, or put them into your rubbish bin instead of into your compost.

However, if you have a ‘hot compost’ system that breaks down food, dairy and weeds much faster, then you are able to compost these items without creating odour. Find out more about hot composting here.

If you always put a carbon layer on top (such as dead leaves and paper), as this will help get rid of the smell from food waste, will prevent flies being attracted to it.

Why is my compost taking so long to break down?

Compost generally takes between 6 weeks to a year to break down, depending on how much effort you put into maintaining it.

Aerating your compost by turning it (with a compost aerator or garden fork) can help your compost break down faster.

‘Compost activators’ such as coffee grounds, manure, or grass clippings are high in nitrogen and will speed up the decomposition process if it hasn’t already started. Otherwise, the compost may be too dry, so you could mix in some water.

Composting information and resources

Simple tips and solutions for beginners through to passionate composters: @compostable.kate

Composting if you move around a lot: https://ethicallykate.com/blog/2019/2/28/how-to-compost-in-your-kitchen

Community composting options via the app ShareWaste: https://www.sharewaste.org.nz

Love Food Hate Waste: Composting 101 https://lovefoodhatewaste.co.nz/composting-101/

What is hot composting and how is it different to traditional composting?

The temperature in a hot compost is usually about 60-70 degrees, and is the fastest way to make compost. Hot compost can break down in as little as 6 weeks to 3 months, depending on what materials are in the pile.

Hot composting is the safest way to get rid of dairy, meat and weeds without sending it to landfill. High temperatures in hot compost can kill bacteria and pathogens, and prevent weed seeds from sprouting.

This method takes more effort compared to cold composting, and due to the larger amount of green and brown waste needed it can be difficult for the average person. This is why it is a much better style of composting for community groups or a large number of people.

How do I start a hot compost pile?

Start your hot compost pile as you would start a regular compost, but add compost activators such as coffee grounds, manure, or grass clippings after the sticks and dead leaves, and before you add your greens. Compost activators are high in nitrogen and will speed up the decomposition process and encourage heat.

As you add to the pile, alternate between different layers of browns (paper, cardboard and dry leaves) and greens (food scraps, animal manure and lawn clippings), with 3 parts browns and 1 part greens. Also add water to create a better environment for microbes to survive and to help them work harder. Add water regularly as the pile loses moisture quickly from the heat it creates.

It is beneficial to have different types of browns and greens to create diversity in the microbes in your compost, which helps to heat up the compost pile.

Why is my compost not getting hot?

If the ratio of greens to browns is out of balance, it can take longer for the temperature to rise. If you can see too much greens, try adding more browns and vice-verse.

You can also try adding more ‘compost activators’ such as coffee grounds, manure, or grass clippings that are high in nitrogen and will speed up the decomposition process and encourage heat. Also, if your compost pile is too dry, the microbes will not find it as easy to break down the materials and your compost will make less heat.

It doesn’t matter much if your compost pile doesn’t reach a high temperature of 60/70 °C, all it means is that the decomposition process will take longer.

My compost is above 70 degrees celsius, is that normal?

Yes, hot compost piles have the ability to reach surprisingly high temperatures, especially if the heap is in full sun on a hot summer's day. At this point, it is necessary to turn the heap (either with a compost aerator or a garden fork), to distribute the heat and keep the environment suitable for the bacteria and microbes.

Hot composting information and resources

Wastebusters: https://www.wastebusters.co.nz/hot-composting/

What is worm farm composting?

Worm farming (also known as vermicomposting) is a great alternative to conventional composting for people who don’t have time to maintain a compost pile but want compost fast.

Worm farms use special worms, either ‘Tiger Worms’ or 'Red Wrigglers', to break down the organic waste into worm castings that can be used to fertilise and feed your garden.

The liquid that drains off the worm castings and decomposing scraps and foliage, called leachate, can also be used to feed your gardens (diluted with water at a ratio of 1:10).

Is it easy keeping a worm farm?

Worm farming is low maintenance and you can feed them almost all of your food waste. They also eat paper and cardboard, so they can eat used paper towels, tissues and dirty pizza boxes that can’t be recycled.

Worm farms are simple to use because you can set up the worm farm, empty your food and green scraps into the box, and leave the worms to do the work. You may need to make small adjustments to the contents of the worm farm every now and then, but worms are usually resilient and will bounce back after any issues.

How do I set up a worm farm?

1. You can buy worm farms from your local DIY or garden centre, or you can make your own using two stackable storage bins with holes in the bottom of the top bin, and holes in the lid of the bottom bin. You’ll also need about 1000 (250g) tiger worms to get started, and can also get them from hardware stores or garden shops, or you could ask someone who you know already has a worm farm.

2. Set up your worm farm container in a cool and shaded area outside, that is easily accessible.

3. Then add bedding material for your worm farm. Worm farm kits will usually come with coir brick, or you can buy it separately. Other bedding materials you could use are: shredded newspaper, paper or cardboard, brown leaves and straw.

4. (Optional) If you have some compost, add some to help get your worm farm started.

5. Add the worms to the bedding. Give them a few days to settle in and get used to the new environment before you add food scraps.

6. Once you start adding food to your worm farm, add in small amounts to start so that the worms are not overwhelmed. The amount of worms will multiply quickly, meaning that you will need to slowly increase how much food you are giving them.

What can and can’t you feed worms?

It is best to only put organic and green waste into your worm farm. This includes food scraps, garden waste, leaves and foliage, glass clippings, paper and cardboard, and animal manure. Worms can only eat the organic materials when they are soft and started to rot, so you could shred or chop the organic items before putting them info your compost pile/bin if there isn’t already decomposing food in your worm farm.

Too much citrus and onion can make the soil too acidic for worms, so only feed your worms small amounts at a time.

Only put very small scraps of meat, dairy or bread in the worm farm. Avoid putting in spices as this can hurt the worm’s skin, and avoid putting in fats or oils. Worms won’t eat bones, so it is best to bury these or put them in the rubbish bin instead.

Be careful to not put too much scraps into the worm bin at once, and don’t forget to feed them for long periods.

Why are the worms in my worm farm inactive?

If the environment that they are living in is not moist enough, this can cause them to become sluggish. To fix this, use some wet, ripped up newspaper and add it to your worm farm.

Why are my worms trying to escape up the side of the worm farm?

This could be because the worm farm is too acidic, causing the worms to be uncomfortable. To fix this, you could add powdered limestone or crushed eggshells as these are high in alkaline. You can get bags of these from gardening or hardware stores. In the future, feed your worms less citrus.

Why are my worms dying?

Common problems that can kill worms are;

• They have too much food. Don’t give them any more food until they have eaten what they already have.
• The worms could be underfed, so ensure that you are regularly giving them food.
• They could also be too hot or too cold. In winter, put them in a place with a lot of sun so they stay warm enough. In Summer, make sure the worm farm is in the shade otherwise the worms are likely to overheat. Tiger worms work most efficiently at temperatures between 10-25 degrees celsius, so at temperatures either side of this, they become sluggish.

Worm farm composting information and resources

Love Food Hate Waste - Worm Farm 101: https://lovefoodhatewaste.co.nz/worm-farms-101-everything-you-need-to-know/