How to Make Organic Compost
Organic compost is a natural fertiliser and soil conditioner for the garden that can be easily made at home.
Any organic material of plant or animal origin can be converted by soil micro-organisms, fungi, insects and earthworms into a rich compost for your garden soil.
A compost heap can be made by simply piling your garden waste in a spare corner of the garden. After adding the material keep the pile covered during the decomposing process with an old carpet or a sheet of weighted down black polythene to trap in heat and help break the heap down more quickly.
Commercially produced covered compost bins and tumblers are readily available and make a tidy and efficient option to contain your compost pile. These bins take up very little room in the garden making them particularly suitable for the smaller garden or when space is at a premium.
If you have a large garden that produces a lot of garden waste I have found having three bins is the ideal number - one for new waste, one for waste in the process of breaking down and a third one for the finished compost ready for use.
Where to place your compost bin
Place your bin on a level surface over open ground for the worms to gain access in a warm, moist location within the garden.
What to put into your compost bin
Material for compost bins can be divided into two categories - Green waste (nitrogen rich) and brown waste (carbon rich) material. The carbon-nitrogen ratio is an important factor in the compost making process. A mix of both high carbon and high nitrogen materials must be present in the pile to provide an adequate food supply for the micro-organisms that breakdown waste and turn it into compost.
Do not put: diseased plants, noxious weeds, cooked vegetables, meat, grease, fat, dairy products or large bones into your compost heap.
Building up your Heap
Begin with a layer of course base of twiggy material to help aeration followed by alternate layers about 10-25cm thick of "green" and "brown" waste. Dampen with water between each layer to help keep the heap moist.
A commercial compost activator can be added to speed up the breakdown of the materials.
How long will it take
The average compost heaps takes about three months to decompose during the summer months and longer during winter.
How do I know when it is ready
When compost is ready it will look like potting mix with a dark brown appearance, crumbly texture and a sweet earthy smell.
Slow to heat up:
If the heap is slow to heat up at first add more "green" material such as animal manure or blood and bone. Drier material such as leaves will decompose more quickly when mixed with moist grass clippings.
Slow to decompose:
The smaller the size of the materials placed in the heap the quicker they will mature. Turn the heap occasionally with a pitchfork or shovel to help the heap rot evenly and to circulate air through the heap.
Heap is too wet:
Keep the bin covered to prevent it getting too wet in heavy rain. If the heap should become too wet add more "brown" material.
Heap is too dry:
A heap should be moist and not allowed it to become too dry. This can happen especially during the summer months.
The heap is slimy or smelly:
This is often caused by insufficient air circulation making the compost unusable. A compost heap needs to be aerated to promote decomposition. Check that the layers are not too thick. Grass clippings tend to form an airless mass and turn into slim due to anaerobic bacteria. This can be prevented by adding a layer of fibrous material for better air circulation such as straw, shredded newspaper or leafy plant matter before adding grass clippings.