Composting Guide

Composting is a really easy way to make use of your garden and kitchen waste, saving it from expensive and environmentally damaging landfill. Over 30% of household waste is recyclable. This means real savings for you and the environment. Compost is also a great sustainable alternative to peat moss. Your garden will love it! Wormeries work in a similar way to composters. Don't miss our full wormeries guide which covers every step.

Home Composting

What is composting?

Composting is a process which turns organic waste—up to 50% of household waste—into rich compost which your garden will love. When a mix of organic waste is composted, a simple process happens. First, tiny micro-organisms like bacteria break down the softer elements of the waste. Once this has been consumed, larger organisms like worms and beetles move in, and work in the tougher parts. By the end of the process the original ingredients have been broken down, mixed together and resemble soil.

A mixture is the key

In composting, 'greens' are fresh plant materials, fruit and vegetable scraps, and coffee and tea waste; while 'browns' are dry and dead plant materials like straw, woods chips, dry weeds and autumn leaves. Greens and browns break down at different rates, and it has been found that you'll need about two parts green waste for every one part brown waste in your compost environment. The greens get the process started, while the browns give body to the compost. Be careful: too much green waste will result in wet, messy compost.

What can be composted?

Basically, anything, which once lived, may be composted. Nearly a half of your household rubbish can be composted, as well as some garden waste.

  • Greens: Garden clippings, leaves, weeds, grass cuttings, fruit and vegetable waste, bread, pasta, rice, tea-bags, and coffee.
  • Browns: Kitchen paper, sawdust, wood shavings, straw, paper, wood, crushed egg-shells, feathers.
  • Don't compost: Meat, fish, bones, grease, butter, oil, glossy paper, weed seeds, nappies, dog and cat litter. (Most of these will attract pests.)

Constructing a compost heap/bin

Depending on your needs, and amount of waste, you'll decide on a heap or a bin. A compost heap is useful for gardeners having large quantities of waste to decompose. Minimum dimensions should be one metre squared and one metre high, enclosed in bricks or timber. A compost bin is better for smaller gardens. Bins may be purchased from us at a very competitive rate, or simply constructed from a large drum with open ends. Remember to put it directly on the ground so earthworms can enter. You may also consider constructing two bins or heaps so material can be accumulated in one while matter is composting in the other.

Getting started

Place your bin close to the kitchen door for ease of access. Think of winter rain! Put it on bare soil or grass (not paving or concrete), so that organisms can get access and excess water can drain away. If you can, break up the ground by digging over it lightly. The bin needs to be in partial shade, and shouldn't be too exposed to the rain. Put in a layer of garden waste like leaves or weeds, a little loose soil, some broken pieces of cardboard and some vegetable peels. Finally, simply let nature take over.

How long does it take?

This is a complex question, depending on the individual composition of your bin, what the weather conditions are like and where the bin is placed. It may take as little as two months—or it could take a year.

Some FAQ's

Why is my compost slimy and smelly?

This is usually caused by too much sappy nitrogen rich material such as grass. Try to find tougher material to balance the mixture. (Add more brown ingredients such as woody material or paper.) If the problem persists, use less grass; perhaps use the grass as a direct mulch on shrub beds.

Why is my compost bin very hot and has a strong smell?

A very hot bin may start to give off ammonia fumes. Reduce the heat by not shredding everything finely, leave more "chunks" of woody material. Try leaving the lid open overnight or in the rain and turn the compost in the bin regularly.

Why does my compost seem to stop altogether in the Winter?

You may have a very cold garden or the area around the composter may have a cold microclimate. Place a layer of used bubble wrap or straw around it to insulate it.

Why is the composting material damp and soggy?

Most home made compost is damper than bought compost, dry it out before use if you wish. Compost plenty of paper and light cardboard-up to half- and only dampen it if the bin gets too dry. The papery material helps to make a drier and more crumbly compost.

Why do I get a lot of flies in the compost bin?

Try putting a 5-10cm layer of torn up paper or grass cuttings on the top of the bin every day and leave the lid open for a few hours.

How do I stop rodents getting into the bin?

Rodents aren't attracted to compost bins but you often see them as nearly all gardens in Ireland have rodents and the odd mouse may investigate. To prevent this place a layer of bird cage wire under the composter and turn up the edges or use a layer of builders mesh at the bottom.

Useful composting links