Friday, July 29, 2011


"Do you think you are educated?  I don't care if you can speak French, you have an MBA, you've travelled the world, you've accumulated plenty of money and you run your own business - you're uneducated if you don't know how to make a compost heap" Satish Kumar, Environmental Activist 2007
Compost Confusion: A lot is written about composting but many people are still confused and fail at their first attempt and then give up - 'the heap didn't break down', 'it went really slimy', 'it just stank and was full of cockroaches' etc. 

I want everyone to be a successful composter because it makes your plants grow better and recycles nutrients that might otherwise have been lost AND - it is deeply satisfying.

So - how do we turn this  - to this?

Here are a few simple tips:
1.  Get the recipe right.  For compost heaps to work they need about 15-20 parts carbon (C)(dry,brown stuff)to one part nitrogen (N)(green stuff/manure).  That's a lot of brown stuff to green.  

To help you - think about how nature feeds itself - say a forest?  What is dropping on the forest floor to replenish it? A lot of leaves, decaying logs, branches, strips of bark, ash from spot fires, fallen flowers, fruit, feathers, shed animal skins, egg shells, decaying bodies of animals and insects etc.  That's a lot of brown stuff to green.  There is a direct correlation here and it's helpful in thinking how compost is made in nature and what you should be putting in your heap (just leave the dead bodies out please!). 

I repeat because it is important - you need more of the carbon (sawdust, coffee grounds, dry leaves, straw, newspaper, kitchen scraps etc.)  than the nitrogen  (fresh pulled weeds, fresh grass clippings, seaweed, fresh manure, stable sweepings etc)

TOP TIP: Keep some sawdust or shredded newspaper next to your bin and add a handful every time you put a load of weeds, kitchen scraps or grass clippings - this way you will be getting the recipe just right.

2.  Keep it simple.  There is no need to go out and spend $500 on a compost bin.  Choose the system that will work for you and your family - one that you will use.  If you don't have enough stuff to fill a compost bin fairly quickly then you may be better off with a small and compact worm farm.
What Kind of Bin:  Compost bins need to be large enough to generate adequate heat – about 55oC – to break down materials and prevent unwelcome guests like cockroaches.   I have always had success with the plastic black bins – the million dollar bins (they are made from recycled banknotes!). However they will generally not get hot enough to kill off seeds – so don’t put invasive weed seeds in there (feed them to the chooks (or worm farm) or ‘hot’ compost them in a black plastic bag).  However, this does mean that beneficial ‘volunteer’ seeds will keep your veggie garden regenerating from the compost you spread around – you will always be getting new tomatoes, parsley, basil, papayas, coriander, dill, cosmos, zinnias, rocket etc. popping up here and there.

If you have a large garden you may opt for a bigger space to make your compost and one of these bays made from recycled wooden pallets is ideal.  Note the black plastic ready to cover the heap when it rains - compost heaps like to be moist but not waterlogged.

3.  Give me a sunny spot.  A lot of people make the mistake of putting their compost bin out of sight/down the back/behind the shed etc.  There are two problems with this.

Firstly: for compost heaps to work they need to be warm and airy.   

Secondly: if it's not convenient you won't use it.   You won't be making trips to them with the kitchen scraps if they are too out of the way. 

Return a little of what you have taken – don’t throw it away.  Composting is part of the natural cycle of life – by returning to the soil what once was living you will be part of that valuable process.  Compost adds life to the soil.  It improves plant growth, increases the capacity of the soil to hold nutrients and water and the ability of plants to resist disease.  

"If we returned our bodies to the soil, and all of our human and organic waste, we would go a long way to solving the earths' soil fertility problems.  Bill Mollinson (co-founder of the  Permaculture Movement) from a lecture I attended in 1988

What to Leave Out:  

  • Dairy products and meat scraps, they can bring maggots.  
  • Too many citrus peels – they rapidly change the pH and kill off the micro-organisms necessary to make the compost work. 
  • Oils and fats.  
  • Large pieces of watermelon skin and pumpkin will attract rats  - chop it up and bury it in the middle of the bin. 
  • Coloured and glossy paper. 
  • Plastics. 
  • Any plant with thorns. 
  • No chemicals.

TOP TIP: Grow some comfrey plants (Symphytum officinale) next to your bin.  Are you ready for this?  Comfrey is a dynamic accumulator which makes it a fantastic compost activator.  Because of its deep root system it is full of 'mined' minerals and nitrogen and gets the whole heap magically working (and you also have a talking point at dinner parties!)

Comfrey growing next to my compost bin - keep it handy!

What Can Go Wrong: 
Foul smells – usually means the heap too wet and has become anaerobic - that means it has stopped working because too much green (nitrogen stuff OR not covered during heavy rain).  Solution - add some brown (carbon stuff a handful of garden lime/ dolomite or wood ash) and turning the heap will help to combat this.  
Not working at all – too cold/dry/or not enough N – add some fresh garden weeds/manure/lawn clippings/comfrey and maybe move to a sunnier spot.

TIP: The smaller the pieces that you put in your compost the quicker it will work.  Weed and prune your garden beds before you mow – use the catcher and you will have a perfect shredded mix to add to the compost heap.

A Little Story:  When I went to visit my brother-in-law in the UK he very proudly showed me his impressive, newly constructed compost bays, but he was just a bit upset that he still didn't have any compost - they weren't working.  When I looked in the first one it was full of grass clippings and when I looked in the second, dry leaves - neither decomposing.  So what had gone wrong?  Well the first was too nitrogen rich and the second too much carbon.  What did we do? Combined the two together, added a couple of bags of old sheep manure he had lying around, watered and covered the heaps and 'hey presto' two working heaps and after about two months lots of lovely compost.  (Oh, and Carl did add the magic ingredient guaranteed to get compost heap working - urine (nitrogen rich and such a dreadful shame to flush it away!)
 What the world needs now is a sense of humus 
What a lovely load of rubbish! 
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