So you want to make your own compost. You get a bin, place it in the garden, and then what do you put in it. Surely, it is clear, you compost your grass cuttings and your vegetable waste. But at this point you have to be careful. Cooked waste, especially meat, should not be placed in a compost bin, as the smell of cooked food attracts rats. Far better to keep cooked food waste in a worm composter, which is sealed to prevent worms getting put and rats getting in. Save the compost bin for uncooked vegetable scraps and garden waste
But there are other materials that can go into compost. Compost bins will take shredded paper, up to about 20%, and they positively benefit from some woody material to balance out the green, nitrogenous stuff. Too much of grass cuttings will result in a compost that accelerates quickly, giving off much steam, but runs out of oxygen and needs constant turning. Woody material slows the process down to a manageable rate.
Some substances are known to be useful. Coffee grounds and tea bags can go in. Hair, be it animal or human, adds nitrogen, as feathers do. Wool waste, known as shoddy, is mulched over rhubarb in its early stages. In the rhubarb industry, which is was strong in South West Yorkshire, waste from woollen mills was collected and applied to the growing rhubarb. Banana peel is particularly useful for the addition of phosphorus, in which it is very high. In addition, seaweed is always beneficial, as it adds micronutrients to the heap. At Heligan gardens in the period up to the First World War gardeners were told that they ought to urinate on the compost heap, as it adds nitrogen.
Egg shells add calcium, but they take some time to digest. Woodash can be added, but it is better laid on the ground. Leaves should never be added to the heap, as they take longer to rot than vegetable waste does and rot in different ways. The compost heaps rots through bacterial decay, whereas the leaves decay through fungal action.
Anything organic will decay and is in theory useful in compost, but it has to be sued in the correctw ay. A compost heap needs regular turning, as it requires oxygen to maintain the decomposition process