The three methods of composting – which do you need in your garden?

Composting is at the forefront this week with the celebration of International Compost Awareness Week, so I thought it would be the perfect time to discuss the difference between the three most common types of composting and what is the best way to utilise each of them in your garden.

Three bin composting, compost bin, or free standing compost

These types of composting are regarded as ‘aerobic compost’ which means there is airflow creating the compost.

WHAT Aerobic composting is where organic matter is decomposed using microorganisms that require oxygen. The microbes in this type of composting occur naturally and live in the moisture that surrounds the organic matter.

HOW In this type of composting, you can process your food scraps, but it is not the best way as they tend to rot before they break down and can create smell and also attract vermin.

I use the above systems to process all my garden waste, greens and browns. Bokashi can also be added to these types of composting as a nitrogen layer.

TOP TIPS It is important to have a layer of sticks at the bottom layer of your compost, as this will create airflow from the bottom. The most important fact to remember when making an aerobic compost is the ratio between carbon and nitrogen.

For beginner gardeners, carbon is the brown matter, leaves, paper etc and the nitrogen is green material, manure, green grass clippings and food. The ratios are usually 25-30 parts carbon to 1 part nitrogen. If there is too much carbon it can slow down the decomposition of the compost.

Remember also, if it is the height of summer, to water each layer – a compost that is too dry won’t break down. Keep your compost bin in a place that gets at least half a day of sun, as the heat will speed up the breaking down of materials into compost.

You can also spray each layer of the compost with EM (Effective Microorganisms) to help speed up the process, remove any smell and add extra microbes

Worm farming

This is an easy, no-hassle way of composting your food scraps and paper.

WHAT The normal worm farm can usually cope with food scraps from a family of 2 to 3. If you like worm farming and have a big family or produce a large amount of food waste, i.e. if you juice every day, you might want to consider making a worm farm out of an old bath.

The juice that comes out of a worm farm is called worm tea and is really valuable in the garden; just like taking a good herbal medicine, it helps the health of your plants. The worm tea won’t burn your plants and can be applied neat or diluted as much as you like. I have found over years that the dilution ratio doesn’t matter. I use a stronger dilution ratio if my plants have been battered by the weather, as it really does improve the cell structure.

HOW A new worm farm can take up to a month to reach an optimum working capacity. Worms in the bin love paper, especially shredded paper, the inside of toilet rolls, handi towels and cardboard that is used in the home.

Please don’t put into your worm farm liquid, shells, fish bones or too many onion or citrus skins. The worm farm can process citrus and onions, but not heaps at once, i.e. if you were making chutney or lemon curd.

TOP TIPS If your worm farm becomes too dry, add some wet paper. Worm farms like to be kept in the shade and above 8 degrees. If you live in a place where you have really cold winters, either wrap your worm farm in cardboard or bring inside the garage or shed.



WHAT Bokashi is a closed fermentation composting system so is anerobic meaning NO air. Bokashi is the most productive, efficient, restorative form of composting in my experience.

Planting in Bokashi has many great benefits for the garden, as it will hold moisture in the ground, increase root structure, give plenty of food for the plants producing nutrient-dense food, which will have a good complex carbohydrate structure, essential for the human body.

HOW Food scraps are added to a bin that either absorbs the juice or the juice is drained. As food waste is added, a bran inoculated with effective microorganisms (EM) is sprinkled on each layer, before firmly closing the lid to seal off the oxygen.

After the bin is full, it is left to ferment for two weeks and then either put into the soil, raised bed or traditional compost. It requires just two weeks in the soil before you are ready to plant in.

TOP TIP If you are planting seeds, you can plant these straight away, as it will take over 2 weeks for the roots to reach the Bokashi. The waste food then turns into soil and you have the added effect of EM in the soil which then will multiply and restore the goodies in the soil.

Personally, I have all three systems as I enjoy the benefits of them all for different uses – aerated compost for my garden plants, prunings and leaves; worm farms for my paper and Bokashi for my food scraps.

Most importantly, how do you compost? I hope this blog inspires you to start composting if you don’t already, or to try another method. And if you have any further questions on composting, please get in touch for the Knowledge Bed in my weekly newsletter when I’m happy to answer your queries.


Happy compost week!


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