Green tips for turning your organic waste into rich compost

Compost is organic matter that has broken down to form a rich, light and friable humus. A healthy garden is a rich producer of organic materials for composting. Here's what you need to know about creating rich compost the right way.

The composting process is fuelled by moisture and air.

• As organic matter breaks down, it heats up.
• The smaller or thinner the ingredients, the faster the rate of decomposition.
• Grass clippings become hot very quickly and assist the rapid breakdown of the other matter.
• The shredded leaves and roots of plants such as legumes or comfrey will also speed the process, but unshredded large leaves, stems, twigs or bark will slow the process down.

• During periods of little rainfall, water the compost weekly; it should be damp but not soggy so if you are using a bin system ensure that drainage is adequate.
• Every few weeks, lightly turn the compost over with a fork to make sure it is properly aerated. The rotting process takes eight to 10 weeks.
• The best approach is to combine a variety of ingredients so that the fast-decaying matter helps accelerate the breakdown of the slow-decaying matter.
• Harvest your crop and compost the left-over stalks, roots or leaves along with straw, grass clippings and manure — these "ingredients" will be broken down by the bacteria in the soil, resulting in a nutrient-rich bed ready for the following season.

Proprietary compost tumblers and bins provide for elaborate, tidy composting, but the easiest and most efficient approach is to layer organic matter in heaps directly onto the ground.

• Earthworms will circulate through the heap, helping to keep the mixture loose. A compost heap on the ground has a side benefit — it is a great way to prepare a new bed for planting.
• When the compost is removed, whatever vegetable matter was growing underneath will be ready for turning over and cultivation.
• If you can afford to leave a bed fallow for a few months, composting on the vegetable patch itself is also worthwhile.

Just about anything that will break down readily is suitable for the compost heap. Most ingredients — particularly large amounts of grass or shredded newspaper — are best thinned out by mixing them thoroughly into the heap rather than leaving them to form a soggy, compressed layer that defies decomposition. Some suggested ingredients are:

• animal manure
• straw, lucerne or hay
• grass clippings
• leaves
• shredded stalks and bark
• kitchen vegetable scraps
• floor sweepings or vacuum-cleaner dust
• seaweed
• mushroom compost
• shredded newspaper
• sawdust or wood shavings

You can create a self-sustaining cycle by recycling all organic materials that are not harvested to eat. Remember these tips and keep kitchen vegetable waste, leaves, grass clippings and shredded prunings for your compost heap!