How to Make Your Own Compost

Making your own compost is a natural way to fertilise your garden, save money, and do your bit for the environment. This guide will show you how to set up a compost bin, the best place to keep it, and how to make your own organic compost that your plants will love.

Composting Basics

Compost is simply decomposed organic waste. Garden waste and fruit and vegetable scraps from the kitchen are all you need to make your own. In just two to three months you can create an ongoing supply of organic fertiliser that’s packed with nutrients your plants will thrive on.

Compost is made in layers, to create a balance of carbon and nitrogen:

• Carbon Layer – This is made up of brown material, like be dried leaves, twigs, pea straw, or newspaper.
• Nitrogen Layer – This is made up of green material, like plant trimmings, grass clippings, or anything green and leafy.
• Enhancements – This can be lime or a compost maker product. Adding this to each layer will help speed up the composting process, and help neutralize acidity. It also has the added bonus of keeping flies away.

Add alternate layers to your bin or pile, making sure you have an even ration of brown to green waste. Then add water and cover.

It’s a good idea to chop up your waste to help it decompose quicker.

Your compost will sit on bare soil, which allows earthworms to enter the compost and help aerate it and decompose it quicker.

The compost is then turned regularly, which also helps aerate and it, and helps decomposition.

Types of Compost Bins

A compost bin will help prevent any animals from getting into your heap and help stop any bad smells. They also retain the warmth and moisture that’s necessary for good compost, and allow good air circulation.

What type of bin or structure you use will depend on how much waste you will have and what space you have available. Here are the main types:

Tumbler Bin

These are ideal for small gardens and courtyards - you can even place them on concrete or pavers. These are one of the easiest ways to compost - just load the barrel then turn it every few days. The materials will mix and aerate to speed decomposition, leaving you with fantastic mulch in just four weeks or rich compost in six weeks. You don’t need to create separate layers in a tumbler bin, but always make sure you have an even amount of green and brown materials.

Square / Round Bin

These are available in a range of sizes and are resistant to weathering, general wear and tear, and made from recycled polypropylene. They’re compact and lightweight.

Wooden

These are easy to assemble and allow you to combine compost with your soil to encourage natural retaining nutrients, moisture, and air for a healthier garden.

Home Made or Heap

You can build your own structure to suit, or you can simply make a pile on the ground.

Indoor System

Mini indoor compost systems, like a Bokashi, are another efficient way to compost food scraps and add moisture to the soil. Food scraps are fermented, which are then dug into your garden or added to your compost. It also creates a juice through the fermentation process, which can be diluted and used as a fertiliser.

Location

Choose a well-drained area, away from the house. It needs to be sheltered from wind and extreme heat. A shady area is best.

Timing

Compost is normally ready in 3-4 months in a tumbler bin, or 9-10 months in a normal compost bin. The end result will be a rich and dark, crumbly compost that will be full of good nutrients for your garden.

Drainage / Ventilation

Whatever type of compost bin you decide to use, it needs to have plenty of drainage through the bottom and adequate ventilation through the sides.

Speeding Up Your Composting

Turning over the compost with a pitch fork every couple of weeks will help the process along. There are also a range of compost accelerator products available, which add extra microbes and enzymes to the mix, encouraging faster breakdown.

How to Set Up a Tumbler Bin

• Choose an area for your bin and set it up.
• Add an equal amount of brown and green material. You do not need to create separate layers in a tumbler bin, as it will all get mixed together.
• Add some lime or compost maker.
• Add some water.
• Spin the tumbler a few times.
• After about 3 months your compost will be ready to use. It should look like soil, and smell earthy.

How to Set Up a Regular Compost Bin

• Choose an area for your bin and set it up on bare earth.
• Start by alternating your brown, green, and enhancement layers.
• Make sure you’re adding equal amounts of brown and green layers.
• Add water and cover.
• Turn with a pitch fork every couple of weeks to aerate it and help speed up the process.
• After 9-10 months your compost will be ready to use in the garden.

How to Set Up An Indoor System

This Bokashi System is a handy way to make use of food scraps from the kitchen. Composting time is increased by 50%, and it is simple to use. Two buckets are nested on top of each other. Food scraps go into the top bucket and ferment, creating a juice that drips through to the bottom bucket. This juice can be diluted and used as fertiliser for your garden.

• Collect cut-up food scraps, and when you have enough add them to the top bucket.
• Add the bag of Compost-Zing. This will help start the fermentation process.
• Cover the bin and place in a warm area in your house, keeping it out of direct sunlight.
• After 7-10 days in Summer, or 10-14 days in Winter, you’ll see the food has been preserved a little like pickles. The fermented food does not break down or decompose while it is in the bucket. You’ll know the fermentation process has been successful, as it will smell like pickles or cider vinegar. You may also see white cotton-like fungi on the surface.
• Your fermented food can now be added to the garden, where it will break down.
• Dig a trench 20-25cms deep and mix it into the soil. Avoid roots as it can burn them.
• After 3-4 weeks the food will have decomposed in your garden.
• Alternatively, you can add the fermented food into an outdoor compost bin.
• Depending on what you are fermenting, a liquid is produced which drains into the bottom bucket.
• Fruit and vegetables tend to release more liquid than other foods. Do not be concerned if little or no liquid is produced.
• The liquid can be diluted to fertilise your garden. Add 1 teaspoon to 5 litres of water and apply directly to the soil. For trees and shrubs add 2 teaspoons to 5 litres of water.
• The liquid concentrate can also be poured directly into kitchen and bathroom drains, toilets or septic systems. The juice will help preven algae build-up and control 
• odours.

What to Compost

Knowing what to compost is important. Too much of the wrong things could end up damaging your plants. These tables will help you get it right.

Waste Material	Value	Tips
Waste water / drinks	Neutral	Your compost heap should be kept moist at all times. Topping it up with water occasionally. Don’t use too much or you’ll end up creating a swamp.
Cardboard	Carbon	Small quantities of cardboard can be good for a compost heap. If you have a large amount it is best to recycle it.
Corn cobs or stalks	Carbon	These are best when shredded, as they’ll break down a lot faster.
Coffee grounds and filters	Nitrogen	Great treat for the worms.
Fruit and fruit peel	Nitrogen	Fleshy peel like banana peel can take longer to decompose, bury them in the middle.
Tumble dryer lint	Carbon	Great for moisture levels.
Egg shells	Calcium	Crush shells as they break down slowly. They are a great obstacle course to keep the slugs and snails away.
Hair	Nitrogen	Sprinkle evenly across the pile.
Dry or green leaves	Carbon	Avoid using diseased plants or bushes.
Manure (chicken, cow, goat, horse, pig, rabbit, sheep)	Nitrogen	Great for speeding up the composting process.
Newspaper	Carbon	Use in small broken down amounts. Consider recycling large amounts.
Pine needles and cones	Carbon	These are slow to break down and have an acidic finish, so use moderately.
Sawdust and wood shavings	Carbon	Very high carbon content so avoid using lots unless you can balance with a lot of nitrogen. Use untreated wood only.
Vegetables	Nitrogen	Bury deep to speed up break down.

 

What Not to Compost

Waste Material	Effect
Ashes from coal, charcoal	Coal ash is an alkali and can throw off or your compost’s PH balance. Some brands of charcoal contain paraffin, wax or other chemicals that you wouldn’t want in your garden.
Dairy (cheese, milk yoghurt)	These won’t add much to the compost but will make it more attractive to pests.
Diseased plants	Using diseased material risks spreading that disease further around your garden.
Fish scraps and bones	Builds unpleasant smells and are attractive to unwanted rodents.
Lemons and limes	While they are fine in small amounts, citrus fruits are highly acidic and may stop the composting process.
Manure (bird, cat, dog)	May contain diseased organisms.
Meat, fat, grease or bones	These are very slow to decompose and oil don’t contribute very much to the soil quality.
Treated wood	The varnish or oils used to treat wood often contain chemicals, which aren’t good for your soil. Even naturally treated wood is likely to be too strong an alkali to benefit your composting.
Weeds	Weeds tend to be highly persistent species that could come back even when removed and placed in compost, it is best to destroy them yourself or dispose of in the rubbish bin.