Compost holds nutrients in the soil until plants can use them, increases the organic content of poor soils, retains moisture in sandy soils and loosens and aerates clay soils making it porous. Composting also saves valuable landfill space, which is becoming increasingly scarce in the Sydney.
In the natural environment, natural composting or decomposition occurs all the time. Organic matter from dead animals and plants is continuously broken down by micro-organisms and small invertebrates. Complex substances are reduced back to simple nutrients, and re-absorbed back by green plants to support new growth.
What can I compost?
- Vegetable and fruit scraps
- Fallen leaves
- Tea leaves and tea bags
- Coffee grounds
- Vacuum cleaner dust
- Soft stems of plants
- Dead flowers
- Used vegetable cooking oil
- Eggshells
- Old newspapers (shredded)
- Lawn-clippings
- Sawdust and wood ash
- Tissues
What cannot be composted?
- Meat and dairy products
- Diseased plants
- Seeds, pods, berries, tubers, bulbs and runners (underground or aboveground)
- Timber products treated with chemicals
- Droppings of meat eating animals
- Fats or oils
- Magazines
- Large branches from trees
- Bread or cake
- Bones
- Plastics
- Metals
- Glass
Maintaining your compost heap
Composting microbes are living organisms and require oxygen for survival. Ensure your compost heap is well ventilated. Turn the compost heap with a garden fork or spade every now and then to ensure adequate aeration. Add bulky materials such as twigs, straw, pine cones and dried leaves to provide plenty of air pockets in your compost heap. If your compost heap smells bad, you may need to aerate your soil more regularly.
Ensure there is sufficient drainage space for excess water flow, and don't allow the compost to become soggy, as this prevents air from getting in.
What's wrong with my compost?
Smell
- Too wet (see below)
- Too acidic. Add some wood ash or dolomite to neutralise the heap
- Insufficient air. Turn more often. Rebuild with some dry materials.
Too Wet
- Improve the drainage under the heap.
- Mix in some dry material such as dry grass clippings or shredded newspaper.
Rats and mice
Rats and mice are attracted to uncovered food in compost heaps and/or the warmth of the heap. To reduce the incidence of rats and mice in your compost bin, cover each addition of food with a layer of soil. Place the bin on a layer of fine wire mesh and set traps around the bin.
Flies
Most of the flies in and around a compost heap are small vinegar flies, which are quite harmless. To deter flies, cover the organic waste with a thin layer of soil, grass or leaves.
If the flies are house flies or blow flies, then they are being attracted by meat, dairy foods or manure. Do not add these materials.
Useful websites
There are many ways to manage your compost. Look at these other useful websites.
Sustainable Gardening Australia - Composting Information
Sydney Water - mulching and composting
For a colour brochure, click on the link below.
- Tips on Composting. (pdf 45kb)