Posted in: Guides
Published: 15 Nov 2017
By definition, composting is the act of recycling food and garden waste, to create nutrient-rich, robust soil called humus. Organic materials are broken down by microorganisms at relatively high, yet stable temperatures. Once decomposed the waste matter can be returned to the soil.
Though proportions vary, the general makeup of compost is:
Organic matter + water, air, carbon- and nitrogen-rich materials, worms, fungi, aerobic bacteria + time
• Organic matter needs oxygen to decompose and when buried by tons of other waste, it does not get the chance to decompose properly, and methane gas is created. Not good for our environment!
• Soil with compost is more nutritious and holds water better
• Soil with compost has more microbes, which makes for healthier soil and protects plants from disease
• Soil with compost needs less watering, fertiliser, and pesticides
• Soil with compost reduces erosion, decreasing the potential for landslides
You’ll need a place for a heap or a compost bin. There is usually a slight odour, don’t worry this will only be coming from the latest additions and it isn’t particularly offensive. It is however worth making sure your compost area is in a quiet corner and not right next to your neighbour’s entertaining area!
Compost bins come in many sizes and styles, all with lids and aeration holes. Air is very important with composting, to not only create nice crumbly compost but to aid the rotting process. If you are composting in a heap, keeping it corralled by a small fence is a good idea. One cubic metre is about the right volume for the most efficient result. A cover is advisable, either a lid or sheet of canvas or similar.
Organic matter should be added in layers, to assist the breaking down and provide aeration.
Alternate the layers of wet / green (kitchen scraps) and dry / brown (leaves and paper) for the best results. See our diagram for how to do this.
Turn the compost regularly if possible, to aerate and aid the decomposition process.
Generally, it takes about 8 - 12 weeks for matter to decompose into nice compost. The compost is ready for use when it looks black and feels just moist and crumbly. The aroma should be fresh and earthy. To speed the process, turn the compost regularly, keep it to around one cubic metre, ensure it stays moist and use shredded materials.
Once your lovely compost is ready, dig it into your garden beds, add to the base of a hole ready for planting, or use it to help break up and aerate poor soils.
It’s advisable not to include lots of citrus peel or capsicum as these can upset the worms; egg shells are great but crush them first for best results; meat scraps can attract flies and rats, so best to avoid those.
Washing all parts of your fruit and vegetables is a good idea, so that you are not adding unwanted pesticides into your compost.
Coffee grounds and tea leaves (remove strings & tags from bags) are great for the garden and compost heap.
Fish: heads, bones, prawn shells and other soft seafood waste is great for the compost, try placing them under a layer of grass to deter vermin.
Grass clippings: These are great, just be sure to add as a layer with coarser, dryer items otherwise the heap could become too hot and the grass clippings can turn slimy.
Pruning offcuts: Throw these in but be sure to cut them up quite small.
Fallen leaves: These are great to include as a brown layer in your compost. Keep in mind that leaves will rot slowly unless they are mixed with other compost material. Using the lawnmower to chop them up can be helpful.
Weeds: Yes, you can include weeds in your compost, but be careful not to include any oxalis, onion weed or seeding weed plants. Pull them well before they go to seed!
Manure: Hebivore manure is a great addition to your compost pile as it adds nitrogen and helps vegetable matter to rot. It is best if the manure is at least a few weeks old before it goes in. Do not add cat or dog manure.
Sawdust: This is the perfect addition to throw in with your manure so it acts like an activator. Check that the sawdust is from non treated wood first!
Carpet fluff, floor sweepings and hair: Did you know you can empty out the vacuum cleaner into your compost pile – genius! Just ensure your carpet is 100% natural fibre as synthetic fibres will not rot. Add your floor sweepings, dryer lint (when drying natural fibres) and the hair from your brush too.
Ash: Ash from burnt wood (not coal) is useful.
Fertiliser: Throwing in any left-over organic fertiliser will always help the heap.
Paper: Newspaper shredded small is fine to add, but avoid glossy magazine paper as this rots slowly and the coatings may not be suitable for nutritious soil. Brown paper bags, paper towels and tissues are all perfect to compost.
Anything synthetic, toxic and inorganic. Remember, your compost will be used to grow plants and nourish the soil, so keeping it free from poisons and pesticides is a top priority.
Plastic, glass and metal; Rubber; Oils; Dairy foods; Cat litter; Cat or dog faeces; Meat and other animal products (excepting fish waste)
Kitchen waste that comes in small pieces, for example coffee grounds or the slurry left behind by your juicer or food mill, disappears so fast when buried that many gardeners dig it into beds that are being actively used to grow plants, including the soil beneath berries and fruit trees. Chunkier materials like broccoli stalks and apple cores take longer to decompose, so it is better to chop them up and bury them in resting beds, well-covered in deep holes or trenches. If possible, give holes and trenches a few weeks to mature before planting, or the nitrogen can be a bit too strong.
Or, you can make a proper compost pit. Dig out a hole and layer in kitchen waste, grass clippings and pulled weeds, then cover it with mulch. Plant three or four plants around the filled compost pit, which also serves as a moisture reservoir in dry weather. Some gardeners make layered compost pits in autumn, and plant tomatoes or pumpkins in the enriched holes in spring.
This is a basic guide to making compost at home, we hope you feel inspired to give it a try! At the very least, composting your waste means less landfill and less toxic landfills, that has to be reason enough.
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