Garden

How to make compost

Composting is not only for farm folk – it’s great for all gardeners!
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There are so many reasons to start composting and getting started is easier than you think.

WATCH: How to build a simple compost system with Charlie

Homemade compost is one of the best soil improvers there is, and also works as a mild fertiliser. 

By making compost, and adding it to your garden, you’ll improve the overall quality of the soil. Plus, there’s something satisfying about giving back to the earth – in the form of rich, nourishing organic matter.

For best results, think of your compost bin as a living thing (a family pet, perhaps?) that shouldn’t be neglected, and requires to be ‘fed’ a balanced diet. Here is what you need to know to get started.

compost bin
Tumbling compost bins are mounted on metal or sturdy plastic brackets (Credit: Getty)

Which bin is best for composting?

Choose a composting container that’s best suited to the available space in your backyard. You’ll find the most common choice for suburban gardens, and the most prevalent on the market, are freestanding sturdy plastic models with lids. You’ll also find compact plastic units that are mounted on metal or sturdy plastic brackets, allowing the drum to be tumbled with ease.

If you’re handy on the tools, and you have the luxury of a little more open space, spend a weekend making a square-shaped compost ‘pen’ from lengths of timber (or decommissioned untreated timber pallets), or create a circular tower assembly with garden stakes and wire mesh. Just remember to allow good aeration, sufficient drainage and easy access.

timber compost
Knock together a compost pen using lengths of timber (Credit: Getty)

What goes in compost?

When you’re ready to start adding waste to your compost heap, you need to think about organic materials as two separate groups – greens and browns.

What are green materials?

Greens (or the wet ingredients) provide nitrogen, and include a balanced mix of vegetable and fruit scraps; coffee grounds and filters; tea bags and leaves; fresh grass clippings; plant trimmings from your garden.

What are brown materials?

Browns (or the dry ingredients) are carbon-rich materials, and include dry leaves; straw and dry hay; woodchips and sawdust from untreated wood; dried grass clippings; shredded newspaper; chopped onion skin.

You should aim to add waste to your compost bin in an approximate ratio of three-parts browns to one-part greens. To speed up the process, add a few handfuls of cow manure and mix it through. Also chop all materials into smaller pieces before adding them to the pile.

composting
Chop materials before adding them to your compost heap (Credit: Getty)

What not to add to compost

Avoid adding meat; fish; eggs; dairy products; oily foods or grease; bones; cat and dog waste; diseased plants and seeds of weedy plants; roots of plants that could generate a whole new plant; anything treated with chemicals or pesticides. Adding egg and nut shells attracts mixed opinions, as they take longer to break down, but you shouldn’t have a problem if you crush them up. The same goes for citrus peel – chop it up well and don’t overdo the quantity of peel.

How to maintain your compost

It’s best to cover a layer of green materials with a layer of brown materials (or dig a shallow hole in the pile and stir the new stuff in so it gets coated with the existing contents). This minimises the presence of flies and covers up bad odours.

That said – composting is a bit of a smelly process. But it shouldn’t be so stinky that you’re receiving complaints. If you notice a your pile is starting to pong, make sure there is sufficient aeration and that you have enough brown materials in the pile. To test your compost, grab a handful – it should feel slightly damp, just like a wrung-out kitchen sponge. If it’s too dry, it needs more moisture. If it’s too wet, add more brown materials. It might take a bit of experimenting to get things just right for your conditions!

compost
Alternate layers of brown and green organic matter (Credit: Getty)

How to know if your compost is ready

When your compost is ready to use in your garden – which could take anywhere from 3 to 12 months – it should look and smell like rich dark soil. If you’re unsure if it’s good to use, place a scoopful in a zip-lock bag and smell it before sealing. Place the bag in a dark spot (a cupboard or drawer is ideal). After a few days, open up the bag – the compost should smell the same as it did before. If it smells worse, your compost needs more time to break down. When each load of compost is ready to use, spread it as mulch on top of all your garden beds and fork in lightly.

Once you get hooked on the process, you might like to start another compost pile next to your first and have them on rotation, providing a steady supply of organic matter for your garden.

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