The Right Mix:
Composting is basically a matter of getting the ‘mix’ right:
- ‘green’ materials
- ‘brown’ materials
- microbes, funghi, bugs, worms etc.
Browns: Drier materials in which carbon content dominates. They include:
- Fallen & dried leaves
- Hay & Straw
- Shredded paper & Cardboard
- Crushed/mulched woody prunings & twigs
- Crushed eggshells
- Mashed corn Cobs
Greens: Materials in which nitrogen content dominates. They include:
- Vegetable & fruit scraps
- Grass Clippings
- Coffee Grounds
- Fresh leaves, hedge trimmings
Note: The distinction that is frequently made between ‘greens’ & ‘browns’ is not necessarily about specific ‘green’ or ‘brown’ materials. As prospective fresh (‘green’) compost materials dry out & start to decompose they can become ‘brown’ (or ‘browner’) as their nitrogen content is lost to the atmosphere & their carbon content becomes more dominant. Composting is just ‘active management’ of this balance and of the natural process of decomposition. It’s all about understanding the composting process, maintaining a suitable balance in your compost mix & keeping our microbial & other tiny friends happy!
So if your compost mix seems to have ‘stalled’ & appears to be going nowhere with nothing breaking down – as a rule of thumb – think about whether it needs:
- more ‘fuel’ (more nitrogen or ‘greens’) or…
- if it needs more air or water (both are needed to maintain bacterial & fungal life).
Adding more ‘greens’ – fresh grass clippings or some chicken manure mixed in makes good ‘rocket-fuel’ for microbial activity! Adding a little water can also get a dry, stalled mix going again – basically the mix needs to be just moist enough to feel damp in the hand (like a damp sponge). If your compost mix becomes overly ‘gluggy’ and starts to smell sour, it’ll just be too wet. Not a problem – turn it thoroughly to allow air in, mix in some straw or other ‘browns’, go easy on the water & it’ll fix itself! If you are using a vertical compost bin a ‘compost screw’ makes turning the mix much easier!
Composting with Horse Manure. Despite concerns about grass seeds & weird ‘worming’ chemicals, horse-manure can be a composter’s dream, especially for those with big gardens to maintain. Your local pony club will usually give the stuff away & it makes for an excellent, ‘finely-tilthed’ composting outcome, although the process can take a bit longer than with other materials. And for the householder with a bigger garden, it allows for composting on a larger scale! You will need to have space for a larger heap, bay or container (an old tank ring works well) & a suitable turning fork. Placing the mix on bare ground seems best as it allows access for worms etc. The following mix seems to work well for house-hold use:
- about 60-70% horse manure
- about 25-35% ‘greens’- coffee grounds, lawn clippings, chicken manure etc
- about 5% straw, shredded card board & other fine ‘browns’.
Horse manure is high in nitrogen (so is quite ‘green’), but as horses only have one stomach and because their stalls & yards are often bedded with straw, bagged manure often ends up containing lots of straw (‘browns’). Which is a very good thing! But it does mean that a horse-manure based compost needs to be:
- larger – usually around 1 cubic metre or more &…
…otherwise the decomposition will take many months. You need a larger volume to hot-compost so you need to be suitably organised. There’s some good information in the two links below!