composting: Part 1

​During September, I will examine the topic of composting.  This is the first blog post in a three-part series which will cover three different composting systems.

Composting is a great way to recycle our waste from nature.  Compost is essential for creating rich soil and healthy plants.  Did you know that it is possible to compost both brown and green materials?

There are three main ways you can compost your waste:

• Composting bin
• Bokashi
• Worm farm

Each system operates differently.  Over the next three blog posts, I will outline each method.  In this post, I will focus on how composting bins work.

Composting bin
You will need some kind of structure to hold the compost, such as a container or bin.  You can buy a ready-made composting bin or build your own from a plastic container or pallet. 

Choose a sunny spot for your compost bin.  Ensure it is easily accessible for adding ingredients and mixing regularly.  Layer your compost, blending carbon (mainly brown waste) and nitrogen (mainly green waste).  Aim for a ratio of 30% green waste and 70% brown waste.  This means adding a mix of organic garden and kitchen waste materials.

Green waste is normally soft, fresh and moist.  Examples of green waste include food waste and fresh green lawn clippings.  Brown waste is normally dry and brittle.  It can therefore take a long time to break down.  Examples of brown waste include dry leaves, paper, cardboard, twigs, wood chips, vacuum dust and dry grass.  Avoid adding meat, dairy products or bread as these can attract unwanted pests.  Don’t add any diseased plant material to avoid spreading the disease.

A good rule of thumb is to add nothing larger than your little finger. Break up larger items like sticks, twigs and cardboard before adding them, to help them break down more quickly. 

Layer the brown and green waste, a bit like a sandwich. Make sure each layer is no thicker than 10 cm.  Start with a brown layer, add a green layer and then another brown layer.   To help get the composting process underway you can add some existing compost to each layer.

Put a lid on your compost bin to enable it to decompose quickly.  Mix regularly.  Compost should be moist like a sponge.  Add water to dry materials.  Make sure there is good air flow.

Compost is ready to harvest when it becomes a sweet, dark, crumbly material and you cannot distinguish the original materials in it.  This normally takes 3-6 months.  Compost should be dug into the soil. Don’t plant directly into compost as this can burn the roots of plants.

Compost has a variety of benefits when used in your garden. It replaces nutrients that have been removed during a growing season, improves soil structure and increases the amount of oxygen available to plants.  Compost also conditions soil, improves moisture retention, increases earthworm activity and improves fertiliser use by plants.

Composting course
The Auckland City Council runs a 2 hour workshop that offers you a basic introduction to the three different types of composting systems covered in this column.  After attending the workshop, you will be entitled to a $40 discount voucher which you can use towards the purchase of any of the three composting systems covered in the course. 

The workshops take place in a variety of locations and are held regularly.  For more information, visit the following webpage: https://compostcollective.org.nz/