Composting

Composting

If there's one thing every organic grower should know, it's how to create nutritious compost. In this lesson, you'll learn how and why you should make it.

Creating your own compost is an integral part of the organic gardening process. Not only does it help you to process all your garden waste and kitchen scraps, but it also provides you with all the nutritional material needed to feed your garden and improve your soil health.

I scatter my own homemade compost on my veg patch annually, although as I don't have the space to produce much, I buy in organic compost too. This replenishes the nutrients that the previous years plants have taken from the soil, while also improving the richness of the soil and creating great soil texture.

Compost also helps to improve the water retention of your soil, and without it, the nutrient density of your soil would deplete over time leading to less healthy and vigorous crops.

The Benefits of Composting at Home

Composting your garden waste creates a closed-loop system. Each year you are using the plants you have grown to feed your compost, which in turn feeds the plants you will grow next year.

Creating good compost means using the right balance of carbon and nitrogen-rich materials.

Carbon-rich materials are:

• wood chips
• cardboard
• twigs
• straw
• hay

Nitrogen-rich materials are:

• grass clippings
• green foliage
• annual weeds

The composting equation:

• 25 - 40% nitrogen-rich materials
• 60 - 75% carbon-based materials

Managing Your Compost

It's important to aerate your compost heap from time to time. This helps to generate heat within your heap which helps it to break down faster.

It's easier to turn your heap if it's the open variety, but if it's a bin with a lid on like mine, you can simply stick a garden fork in and turn it around once a month.

If you find that your heap is very dry, then introduce more nitrogen-rich material like grass clippings to add moisture. If your heap is very wet, then add more carbon.

Creating a Compost Heap in Your Garden

In a perfect world, I'd love to have a three-bay composting system, where you turn your compost from bay to bay as it breaks down and by the third bay it is ready to use. But like many people, I simply don't have the space for this.

So in my garden, I have one of the lidded plastic bins that are available from local councils. Although like many gardeners I was initially sceptical, these bins can produce great compost as long as you monitor what is going on inside and aerate it at least once a month with a garden fork.

Using a Plastic Bin Composter

Things to Put in Your Composter

Nitrogen-rich

• Kitchen scraps (steer clear of too much citrus or onions)
• Garden waste (foliage, spent plants, grass clippings, annual weeds)

Carbon-rich

• Straw or hay
• Shredded cardboard
• Wood chips

I layer these two types of materials together and take the lid off regularly so I can monitor what is happening inside my bin. This method of composting is known as cold composting and will produce good compost within 9 to 12 months.

Choosing the Right Site for Your Compost Bin

Some rules for situating your compost heap:

• keep your heap in a shady spot out of direct sunlight (so it won't dry out)
• build your heap on a flat site if possible
• keep your heap in direct contact with the earth so that the soil life beneath can get into your heap and aid decomposition

How to Know When Your Compost Is Ready to Use

You can tell that compost is ready to use when it has the following characteristics:

• dark in colour
• crumbly in texture
• smelling slightly sweet

What Shouldn't You Put on Your Compost Heap?

There are a few things that you want to avoid putting on your compost heap if you want to keep it healthy, these include:

• cooked food
• meat and dairy
• diseased plant material
• perennial weed roots
• annual weed seed heads
• cardboard with packing tape or plastic on

Note: To learn more about making microbially rich compost take the Land Gardeners' course 'How to heal your soil'.