Composting 101

Contents:

• What is compost?
• How to start composting
• Where to put your compost bin
• What to put in your compost bin
• How to make compost
• What to do with your compost

Making compost is easy, and it’s free. Our households and neighbourhoods are loaded with organic materials that can be converted into nature’s gold. All you need to do is pile them up, add moisture, then stand back and let nature do its thing. If you’re prepared to put in a little more effort, the materials will break down more quickly, which means you can be putting your compost to good use much earlier.

What is compost?

Compost is a nutrient-rich, organic material that is produced through the decomposition of organic matter such as kitchen scraps, yard waste, and other biodegradable materials. It is commonly used as a soil amendment to improve soil fertility, structure, and moisture retention. Overall, composting is a sustainable practice that helps reduce waste, enrich soil, and support healthy plant growth.

For information on composting as a sustainable practice, check out Hannah Moloney’s article, here.

How to start composting

Bin
The simplest way to make compost is in an open pile on the ground, but it’s much tidier to contain the materials in a closed bin or bay. There are many commercial compost bins available, normally made from heavy-grade plastic. Some come with a small door or removable panel at the bottom, allowing for easy harvesting of the finished compost. Most types come with a lid to keep animals out. It’s also a good idea to bury the base 10cm or so to stop rodents getting in.

Bay
You can also make a compost bay from recycled materials, such as fence palings, timber pallets, corrugated iron or wire mesh. Include a removable front in your design for easy access to the pile, and add a hinged timber lid to stop animals jumping in. Add a few aeration holes in the sides, and cover all holes and gaps with small-gauge wire mesh to stop hungry rodents getting into your compost. That goes for airholes in commercial bins, too.

Compost tumbler
If you want something that’s reasonably mobile, consider using a compost tumbler. This is basically a barrel on a stand, with a few tiny holes for aeration and a small door for adding materials and removing finished compost. It also has a handle or some other system for turning the barrel, which allows easy mixing and aerating of the materials. Some compost tumblers include a ratchet system that makes it much easier to turn heavy loads. Tumblers with dual chambers allow you to fill one side with materials while the materials in the other side are breaking down.

Worm farm
The humble worm farm harnesses the power of compost worms (Eisenia fetida). It can be homemade or come in a range of shapes and sizes from your local nursery or hardware store, and it can easily be tucked away in a large backyard or a balcony garden. It just needs good drainage, worm bedding (aged sawdust), a worm blanket (a damp hessian sack or cardboard) and a lid. Want to learn how to make a DIY worm farm? Read here.

Don’t have the space for a big, bulky bin? Phil Dudman suggests some compact composting options here.

Where to put your compost bin

Place your compost bin or bay directly on the ground so all the organisms that help to break down the materials have easy access to the treats. Choose a site that’s shady, well drained and reasonably level. While a well-maintained compost system shouldn’t smell, there’s a chance it will at times, so don’t place it where neighbours are likely to complain.

What to put in your compost bin

Most things that were once living can be composted: leaves, grass clippings, plant trimmings, fruit and vegie scraps (including citrus and onion), animal manures, tea leaves, coffee grounds, newspaper, cardboard and woodchips. Don’t put pet droppings in your compost, as there’s a risk of spreading diseases, and don’t include meat, fish, bones, dairy and oil, which attract cats, dogs and rodents. Also, avoid adding weed seeds and bulbous weeds that might survive the composting process and be spread around the garden.

How to make compost

1. GET THE BLEND RIGHT To break down efficiently, a compost pile needs a balance of high-nitrogen (green) and high-carbon (brown) materials. Green materials include kitchen scraps, coffee grounds, tea leaves, fresh lawn clippings, weeds, garden trimmings, and poultry, sheep, cow, horse and goat manures. Brown materials include straw, dry leaves, dry lawn clippings, woodchips, wood shavings, and shredded cardboard or paper. For every bucket of kitchen waste or other ‘green’ materials added, toss in a half to full bucket of dry or ‘brown’ materials to maintain balance.

2. CHOP UP MATERIALS When the materials you add to the pile are chopped or chipped into small pieces, it increases their surface area, which increases microbial activity and the rate at which the materials break down.

3. AERATE THE PILE Microbes need air. When the pile starts to slump, turn it over with a garden fork to aerate it, or use one of those giant corkscrew aerators, which makes it a breeze. Aerating the heap increases microbial activity and speeds up the breakdown of the materials.

4. MANAGE MOISTURE Microbes also need moisture, but not too much. To test whether your compost pile needs any extra water, squeeze a handful of the mixture. It should feel just moist, not dripping wet. If your compost pile doesn’t have a lid, cover it with cardboard or a hessian sack to help hold in the moisture. When you have days of heavy rain, throw a tarp over it to stop the compost getting too wet. A compost pile that contains too much green material will often be too wet. If that’s the case, mix through some additional brown materials to restore the balance.

What to do with your compost

There are many more ways to make use of your homemade compost than simply digging it into the soil. For three handy ideas for making the most of your prized compost mix, read here.

Text by Phil Dudman and Hannah Moloney
Header image credit: iStock