Ratio of Woody Material to Soft Material: Brown to green/carbon to nitrogen/C to N – for a compost heap to work well this ratio is very important (happy bacteria).
Too high in carbon/hard material – the heap will dry out rather than compost, too high in nitrogen/soft material – acidic fermentation, slimy smelly heap.
The ideal ratio is 25-30 carbon to 1 of nitrogen. Grass clippings ( high N) Straw and chopped dry stalks ( High C) Chopped garden refuse – old bedding, tops of vegetables etc (N) Shredded paper or bark(C)