Hi Guest green manure isn't composting as such you sow a crop of something like field beans and allow it to grow right through the winter digging it in in spring time about two weeks before you want to sow/plant out your veggies. There are other green manures such as phacellia, clover and mustard but these are sown in spring and dug in during the autumn, so are only useful if you rotation allows for this. The advantage of sowing a green manure crop is that, especially with the field beans, it will fix nitrogen into the soil. We are still experimenting with.