Compost pile

Making compost

Garden Life
Tips from Sarah the Gardener

As the summer growing season comes to an end, and the last vestiges of what was once a verdant garden is cleared away, nothing need be wasted. The remains of the garden can be utilised to nourish future crops with a rich organic compost. It is a wonderful way to improve the quality of your soil and replace the goodness that has been taken from the garden during the previous growing season.

The benefits of compost are numerous. It can assist with moisture retention, improve soil structure, feed soil organisms and attract earthworms. Compost gradually makes nutrients available for the growing plants and can improve health and disease-resistance in the plants. A good quality compost can also increase the quality and quantity of the harvest. It is a crucial resource for any keen gardener looking for a successful outcome.

Compost is readily available in bags or even by the trailer load at garden centres and landscape suppliers and when starting out it is good to add a generous amount to your new garden beds. However, it isn’t something you need to do just once at the start of the gardening journey. For a healthy garden, compost needs to be added regularly to ensure the nutrients used by the previous plants are replaced. Failing to do this in an active garden can result in poor quality plants as the nutrients in the soil become depleted.

However, to purchase compost over the long term can be a little costly, but on the positive side, it isn’t difficult to make at home and it uses the waste products from your garden, among other things. The edible parts of many plants grown in a vegetable garden are only a small part of the plant and by the end of the season you can accumulate a significant amount of garden waste, which needn’t be wasted as this material forms the key ingredients for making compost. When you make it yourself you have complete control over what goes into it and how it is treated.

Compost ingredients

Compost ingredients

Compost is easy to make, but there are a few key points to follow in order to get the best possible outcome for your garden.

Not all garden waste is equal. Some are high in carbon and are often referred to as brown materials, which are generally dry, brown and crispy. They contribute to the aeration of the compost pile which is important. Others are high in nitrogen and are called green materials. These are generally fresh, moist and green. The perfect balance of brown and green material is a ratio of 2:1. This provides the best conditions for the micro organisms to go about their business of breaking the material down into a rich soil conditioner. If there is too much brown it will take much longer to rot down and if it is too green it can become slimy and stinky. Even if the balance is not quite right though it will all break down eventually.

Carbon-rich brown materials include:

  • Cardboard
  • Dry corn stalks
  • Dry leaves
  • Sawdust
  • Shredded paper
  • Straw
  • Twigs
  • Wood chips

It may be beneficial to chop these materials into small pieces to help speed up the process.

Nitrogen-rich green materials include:

  • Coffee grounds
  • General garden waste
  • Grass clippings
  • Pruning waste
  • Seaweed
  • Vegetable scraps
  • Well-rotted vegetarian and chicken manure
  • Young weeds

It is important NOT to add the following to the compost pile:

  • Brightly printed papers
  • Cooked food
  • Fats and oils
  • Diseased plant materials
  • Manure from meat eating creatures
  • Meat and dairy products
  • Plants covered in pests
  • Weed seeds and weeds that don’t seem to want to die.

Industrial-sized compost operations can generally get hot enough to take care of these ingredients, however the average home compost system cannot generally get hot enough to destroy the pests, disease, seeds and stubborn weeds. These items should be put out with the rubbish or burnt.

They can add toxic ingredients, attract rats and other vermin. They can also introduce disease that is harmful to plants and humans. They can allow pests to overwinter in a warm place and can spread weeds across the entire garden making caring for the garden an arduous chore.


Compost containers

Compost methods

There is more than one way to make compost and so there is a method to suit everyone.

Cold composting

The easiest, but slowest way is to make a pile at the end of the garden and eventually it will all rot down. This generally takes about a year to see a result. A three-bin compost system is great for this method, so you have one bin being filled, one rotting down and the third ready and being used about the garden.

Hot composting

This is when you can help speed things up by making sure the ratios of brown and green are perfectly balanced. As the microorganisms get stuck into the process of breaking down the materials, the pile heats up. You can assist this process further by turning the compost regularly. This process can be done in as little as several weeks and up to several months. It is more labour intensive than leaving it in a pile at the end of the garden, but the results are worth it.

Other compost techniques include:

  • Closed bins – these can be purchased at most garden centres and are commonly black plastic boxes that use cold processing to make compost. They are ideal for small yards; however, the amount of compost is limited by the size of the bin.
  • Open bins – This can be as simple as some chicken wire wrapped around some stakes, some old pallets tied together, or an elaborate structure built from timber. It keeps the pile contained.
  • Pit Composting – also known as trenching, where compostable materials are added to a hole or trench in the garden and when full the hole or trench is covered back over with soil. It can take 6 months to a year for the materials to rot down and is more suited to long term enriching of the soil in situ.
  • Tumbler – this is a drum shaped system, where you load it up and give it a turn every time you wander past. This produces compost faster than a compost pile as the contents are being aerated each time it is turned, although due to the size of the bin the batches are small.

However, you choose to make your compost, in time you will have a wonderful soil conditioner to reinvigorate your soil each season and save you a bit of money too!


Important Notice: When using composts and potting mixes, there is always a risk of Legionnaires disease. It comes from a naturally occurring soil-borne bacteria that can be inhaled if the soil or compost you are working with is particularly dusty. It is a good idea to wear gloves while working in the garden and wear a mask if there is a risk of breathing in soil particles or you are working in dusty conditions.